Remove special logic for TypeConverterAttribute

[jtschuster]

Fixes #1942

We no longer need special logic for TypeConverterAttributes. This removes that code, and adds a test to reproduce the issue found in #1942.

[marek-safar]

Are the annotations correct in .NET6 release so targeting LTS from net7 works as expected?

[eerhardt]

Are the annotations correct in .NET6 release so targeting LTS from net7 works as expected?

Yes. See dotnet/runtime#39144. TypeConverterAttribute was made trim-compatible in .NET 5.

@agocke @vitek-karas @jtschuster - Is there any chance this change can be backported to .NET 6 for Maui? I'm seeing the following warnings 330 times when trimming a Maui app, which is causing A LOT of noise.

ILLink : Trim analysis warning IL2111: Microsoft.Maui.Controls.VisualElement.Visual: Method 'Microsoft.Maui.Controls.VisualTypeConverter.CreateVisual(Type)' with parameters or return value with `DynamicallyAccessedMembersAttribute` is accessed via reflection. Trimmer can't guarantee availability of the requirements of the method. [C:\git\WeatherTwentyOne\src\WeatherTwentyOne\WeatherTwentyOne.csproj]
ILLink : Trim analysis warning IL2111: Microsoft.Maui.Controls.VisualElement.Visual: Method 'Microsoft.Maui.Controls.VisualTypeConverter.CreateVisual(Type)' with parameters or return value with `DynamicallyAccessedMembersAttribute` is accessed via reflection. Trimmer can't guarantee availability of the requirements of the method. [C:\git\WeatherTwentyOne\src\WeatherTwentyOne\WeatherTwentyOne.csproj]
ILLink : Trim analysis warning IL2111: Microsoft.Maui.Controls.VisualElement.Visual: Method 'Microsoft.Maui.Controls.VisualTypeConverter.CreateVisual(Type)' with parameters or return value with `DynamicallyAccessedMembersAttribute` is accessed via reflection. Trimmer can't guarantee availability of the requirements of the method. [C:\git\WeatherTwentyOne\src\WeatherTwentyOne\WeatherTwentyOne.csproj]
ILLink : Trim analysis warning IL2111: Microsoft.Maui.Controls.VisualElement.Visual: Method 'Microsoft.Maui.Controls.VisualTypeConverter.CreateVisual(Type)' with parameters or return value with `DynamicallyAccessedMembersAttribute` is accessed via reflection. Trimmer can't guarantee availability of the requirements of the method. [C:\git\WeatherTwentyOne\src\WeatherTwentyOne\WeatherTwentyOne.csproj]
ILLink : Trim analysis warning IL2111: Microsoft.Maui.Controls.VisualElement.Visual: Method 'Microsoft.Maui.Controls.VisualTypeConverter.CreateVisual(Type)' with parameters or return value with `DynamicallyAccessedMembersAttribute` is accessed via reflection. Trimmer can't guarantee availability of the requirements of the method. [C:\git\WeatherTwentyOne\src\WeatherTwentyOne\WeatherTwentyOne.csproj]
ILLink : Trim analysis warning IL2111: Microsoft.Maui.Controls.VisualElement.Visual: Method 'Microsoft.Maui.Controls.VisualTypeConverter.CreateVisual(Type)' with parameters or return value with `DynamicallyAccessedMembersAttribute` is accessed via reflection. Trimmer can't guarantee availability of the requirements of the method. [C:\git\WeatherTwentyOne\src\WeatherTwentyOne\WeatherTwentyOne.csproj]
ILLink : Trim analysis warning IL2111: Microsoft.Maui.Controls.VisualElement.Visual: Method 'Microsoft.Maui.Controls.VisualTypeConverter.CreateVisual(Type)' with parameters or return value with `DynamicallyAccessedMembersAttribute` is accessed via reflection. Trimmer can't guarantee availability of the requirements of the method. [C:\git\WeatherTwentyOne\src\WeatherTwentyOne\WeatherTwentyOne.csproj]

In case you are curious, I explained the reason these warnings occur here.

[agocke]

Given that this is an SDK-only change with high impact, I think it has a chance.