Removed:
* Major components:
* TabView/TabViewItem
* HeaderedTextBlock
* FacebookService and Microsoft.Toolkit.Uwp.Services project
* RSS Parsers
* Smaller methods:
* StringExtensions.ToSafeString
* LinkedIn, Twitter and Weibo sync Logout methods.
* ConnectedAnimations.SetListDataItemForNextConnectedAnnimation
* TileControl.IsCompositionSupported
* NotifyTaskCompletion
* Singleton
This is still missing the update on the docs repo.
## Contributes towards #3062
## Fixes#3396
## PR Type
What kind of change does this PR introduce?
<!-- Please uncomment one or more that apply to this PR. -->
<!-- - Bugfix -->
<!-- - Feature -->
<!-- - Code style update (formatting) -->
<!-- - Refactoring (no functional changes, no api changes) -->
<!-- - Build or CI related changes -->
<!-- - Documentation content changes -->
<!-- - Sample app changes -->
- Other... Please describe: Removing dead code.
## What is the current behavior?
Obsolete classes marked as obsolete, but still exist in code.
## What is the new behavior?
Some classes/methods marked as obsolete are now removed from code.
## PR Checklist
Please check if your PR fulfills the following requirements:
- [X] Tested code with current [supported SDKs](../readme.md#supported)
- [ ] Pull Request has been submitted to the documentation repository [instructions](..\contributing.md#docs). Link: <!-- docs PR link -->
- [X] Sample in sample app has been added / updated (for bug fixes / features)
- [ ] Icon has been created (if new sample) following the [Thumbnail Style Guide and templates](https://github.com/windows-toolkit/WindowsCommunityToolkit-design-assets)
- [ ] Tests for the changes have been added (for bug fixes / features) (if applicable)
- [X] Header has been added to all new source files (run *build/UpdateHeaders.bat*)
- [ ] Contains **NO** breaking changes
This PR IS a breaking change, as instead of just providing a warning, any developers that uses the dead code will now get missing method/class exceptions.
