[WIP] TabViewItem close button custom tooltip

[Felix-Dev]

Description

This PR adds a custom tooltip to the Close button of the tab items of a TabView. The tooltip will describe the action taken on button click as well as the keyboard shortcut used to invoke tab closing.

Motivation and Context

Closes #2018.

How Has This Been Tested?

Tested visually for now.

Screenshots (if appropriate):

Tooltip with available keyboard accelerator (RS3+):

Tooltip without keyboard accelerator:

Open Questions

1. Currently, the keyboard accelerator text, if available, displays (Ctrl+F4) independently from the chosen language. Optimally, localized values will be provided (such as (Strg+F4) for German).
2. When adding localization for "Close tab" I noticed the Automation name for the Close button (which I based the tooltip localization on) is missing for the following languages:
   be-BY, bn-BD, sw-KE, uz-Latn-UZ
   Each of them has an Automation name and localized tooltip content for the TabView's Add button though. Because the Automation name is missing for them, I also did not add a localized tooltip text for the Close button for these languages.
3. See comments in TabView.cpp/.h and TabViewItem.cpp for specific implementation questions.

[msftclas]

All CLA requirements met.

[StephenLPeters]

/azp run

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