[v12] Enable Mac Catalyst in Avalonia.iOS (#19415)

* [v12] Enable Mac Catalyst in Avalonia.iOS

* Consolidate UIKit ControlCatalog csproj files

* Fix the plist

* Split csproj files again

* Update .gitignore

* Desktop Mode

* Storage

* Add maccatalyst as workload target

* Revert .gitignore

azure-pipelines.yml

@@ -80,7 +80,7 @@ jobs:
     displayName: 'Install Workloads'
     inputs:
       script: |
-       dotnet workload install android ios macos wasm-tools
+       dotnet workload install android ios maccatalyst macos wasm-tools
   
   - task: CmdLine@2
     displayName: 'Generate avalonia-native'
@@ -154,7 +154,7 @@ jobs:
     displayName: 'Install Workloads'
     inputs:
       script: |
-       dotnet workload install android ios tvos wasm-tools
+       dotnet workload install android maccatalyst ios tvos wasm-tools
 
   - task: CmdLine@2
     displayName: 'Install Nuke'