[Settings] Optimizing and cleaning up code (#44721)

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fix/what does it change/how was it tested (even manually, if necessary)?
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## Summary of the Pull Request

- Removing dead experiments code
- Refactoring and simplifying OOBE/SCOOBE windowing code
- Removing dead assets
- Optimizing CmdPal assets to lower res shaving off a few MBs
- Scrolling works better on the What's new page
- Should be merged after: #44638

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## PR Checklist

- [X] Closes: #44958
<!-- - [ ] Closes: #yyy (add separate lines for additional resolved
issues) -->
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

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or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments

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---------

Co-authored-by: Gordon Lam (SH) <yeelam@microsoft.com>

src/settings-ui/Settings.UI/PowerToys.Settings.csproj

@@ -28,8 +28,6 @@
 		<None Remove="Assets\Settings\Icons\Models\WindowsML.svg" />
 		<None Remove="Assets\Settings\Modules\APDialog.dark.png" />
 		<None Remove="Assets\Settings\Modules\APDialog.light.png" />
-		<None Remove="Assets\Settings\Modules\CmdPal_Background.png" />
-		<None Remove="Assets\Settings\Modules\CmdPal_Hero.png" />
 		<None Remove="Assets\Settings\Modules\LightSwitch.png" />
 		<None Remove="SettingsXAML\Controls\Dashboard\CheckUpdateControl.xaml" />
 		<None Remove="SettingsXAML\Controls\Dashboard\ShortcutConflictControl.xaml" />
@@ -115,7 +113,6 @@
 		<!-- HACK: Common.UI is referenced, even if it is not used, to force dll versions to be the same as in other projects that use it. It's still unclear why this is the case, but this is need for flattening the install directory. -->
 		<ProjectReference Include="..\..\common\Common.Search\Common.Search.csproj" />
 		<ProjectReference Include="..\..\common\Common.UI\Common.UI.csproj" />
-		<ProjectReference Include="..\..\common\AllExperiments\AllExperiments.csproj" />
 		<ProjectReference Include="..\..\common\GPOWrapper\GPOWrapper.vcxproj" />
 		<ProjectReference Include="..\..\common\interop\PowerToys.Interop.vcxproj" />
 		<ProjectReference Include="..\..\modules\ZoomIt\ZoomItSettingsInterop\ZoomItSettingsInterop.vcxproj" />