Trim application to reduce size

[nikeee]

Windows Forms applications are not (yet?) supported for trimming. However, we might want to do it on some of our libraries.

Some pointers:

• https://docs.microsoft.com/en-us/dotnet/core/deploying/prepare-libraries-for-trimming
• https://docs.microsoft.com/en-us/dotnet/core/deploying/trim-self-contained
• https://docs.microsoft.com/en-us/dotnet/core/deploying/trimming-options

[nikeee]

Blocked by dotnet/winforms#4649