Fixes #3691 - Adds ViewArrangement.Popover (#3852)

* Added Applicaton.Popover.
Refactored FindDeepestView

* Popover prototype

* Testing highlight

* Fixed click outside issue

* Fixed DialogTests

* Fixed click outside issue (agbain)

* Enabled mouse wheel in Bar

* Enabled mouse wheel in Bar

* Progress. Broke arrangement

* Added popover tests.
Fixed a bunch more CM issues related ot unreliable unit tests.
Updated config.json to include Glyphs.

* Can't set ForceDriver to empty in Resources/config.json.

* added BUGBUG

* Made Position/ScreenPosition clear

* Added View.IsInHierarchy tests

* Added Contextmenuv2 scenario.

* Implemented CM2 in TextView

* Removed unneeded CM stuff from testhelpers

* Shortcut API docs

* Fixed keybinding unit tests

* Fixed mouse handling

* Fighting with CM related unit test failures

* Unit tests pass. I think.

* Shortcut code cleanup

* TextView uses new CM2

* Starting on OnSelect etc...

* Starting on OnSelect etc...

* Fixed ContextMenuv2

* ContextMenu is working again.

* Ugh. ANd fixed button api docs

* Fixed DrawHorizontalShadowTransparent (vertical was already fixed).

* Made Scenarios compatible with #nullable enable

* Undid some keybinding stuff

* Fixed stuff

* Sped up unit tests

* Sped up unit tests 2

* Sped up unit tests 3

* Messing with menus

* merged latest v2_develop

* Added more Popover unit tests

* Added more Popover unit tests2

* Fixed positioning bug

* Fixed mouse bug

* Fixed Bar draw issue

* WIP

* merge v2_develop

* CM2 sorta works

* Enabled Bar subclasses to have IDesignable

* Added ViewportSettings.Transparent

* Region -> nullable enable

* Added ViewportSettigs Editor

* merged v2_develop part 2

* merged v2_develop part 3

* WIP: GetViewsUnderMouse

* WIP: More GetViewsUnderMouse work

* Bars works again

* Added unit tests

* CM now works

* MenuItemv2 POC

* SubMenu POC

* CommandNotBound

* More POC

* Optimize Margin to not defer draw if there's no shadow

* Logger cleanup

* Reverted Generic

* Cascading mostly working

* fixed layout bug

* API docs

* API docs

* Fixed cascade

* Events basically work

* code cleanup

* Fixed IsDefault bug;

* Enabled hotkey support

* Made context-menu-like

* Improved usability

* Refactored ApplicationPopover again

* Cleanup

* Menuv2 POC basically complete

* Code Cleanup

* Made menu API simpler

* Fixed Strings bugs

* Got old ContextMenu scenario mostly working

* ContextMenu scenario now works

* ContextMenu fixes

* ContextMenu fixes

* Tons of menu cleanup

* ContextMenu works in TextView

* Fixed unit tes

* Added unit tests

* Fixed tests

* code cleanup

* More code cleanup

* Deep dive

* scenario

* typos

* Demo colorpicker in a Menu

* Added Region tests proving Region is broken in some Union cases

* fixed v2win/net

docfx/docs/Popovers.md

@@ -0,0 +1,18 @@
+# Popovers Deep Dive
+
+Normally Views cannot draw outside of their `Viewport`. Options for influencing content outside of the `Viewport` include:
+
+1) Modifying the `Border` behavior
+2) Modifying the `Margin` behavior
+3) Using @Terminal.Gui.Application.Popover
+
+Popovers are useful for scenarios such as menus, autocomplete popups, and drop-down combo boxes.
+
+A Popover is any View that meets these characteristics"
+
+- Implements the @Terminal.Gui.IPopover interface 
+- Is Focusable (`CetFocus = true`)
+- Is Transparent (`ViewportSettings = ViewportSettings.Transparent | ViewportSettings.TransparentMouse`
+- Sets `Visible = false` when it receives `Application.QuitKey`
+
+@Terminal.Gui.PopoverMenu provides a sophisticated implementation.

docfx/docs/index.md

@@ -33,6 +33,7 @@ See [What's New in V2 For more](newinv2.md).
 * [Mouse API](mouse.md)
 * [Multi-tasking and the Application Main Loop](mainloop.md)
 * [Navigation](navigation.md)
+* [Popovers](Popovers.md)
 * [View Deep Dive](View.md)
 * [Views](views.md)
 * [Scrolling Deep Dive](scrolling.md)

docfx/docs/logging.md

@@ -1,14 +1,20 @@
 # Logging
 
-Logging has come to Terminal.Gui! You can now enable comprehensive logging of the internals of the libray. This can help diagnose issues with specific terminals, keyboard cultures and/or operating system specific issues.
+Logging has come to Terminal.Gui! You can now enable comprehensive logging of the internals of the library. This can help diagnose issues with specific terminals, keyboard cultures and/or operating system specific issues.
 
-To enable file logging you should set the static property `Logging.Logger` to an instance of `Microsoft.Extensions.Logging.ILogger`.  If your program already uses logging you can provide a shared instance or instance from Dependency Injection (DI).
+To enable file logging you should set the static property `Logging.Logger` to an instance of `Microsoft.Extensions.Logging.ILogger`. If your program already uses logging you can provide a shared instance or instance from Dependency Injection (DI).
 
 Alternatively you can create a new log to ensure only Terminal.Gui logs appear.
 
-Any logging framework will work  (Serilog, NLog, Log4Net etc) but you should ensure you only log to File or UDP etc (i.e. not to console!).
+Any logging framework will work (Serilog, NLog, Log4Net etc) but you should ensure you don't log to the stdout console (File, Debug Output, or UDP etc... are all fine).
 
-## Worked example with Serilog to file
+## UICatalog
+
+UI Catalog has built-in UI for logging. It logs to both the debug console and a file. By default it only logs at the `Warning` level. 
+
+![UICatalog Logging](../images/UICatalog_Logging.png)
+
+## Example with Serilog to file
 
 Here is an example of how to add logging of Terminal.Gui internals to your program using Serilog file log.
 
@@ -81,7 +87,7 @@ Example logs:
 
 ## Metrics
 
-If you are finding that the UI is slow or unresponsive - or are just interested in performance metrics.  You can see these by instaling the `dotnet-counter` tool and running it for your process.
+If you are finding that the UI is slow or unresponsive - or are just interested in performance metrics. You can see these by installing the `dotnet-counter` tool and running it for your process.
 
 ```
 dotnet tool install dotnet-counters --global

docfx/docs/toc.yml

@@ -30,6 +30,8 @@
   href: mainloop.md
 - name: Navigation
   href: navigation.md
+- name: Popovers
+  href: Popovers.md
 - name: View Deep Dive
   href: View.md  
 - name: View List