NativeAOT: Trimming and extensions compatibility - implementation

[ivanpovazan]

Based on the discussion: dotnet/runtime#86649 we have identified the following list of issues which should improve compatibility between mobile platform builds and ILCompiler and improve performance:

• Research injecting an interface to resolve open generic members and types to closed ones in the managed static registrar #18356
• Research injecting a constructor to avoid reflection in NSObject.AllocateNSObject in the managed static registrar #18357
• Research improving finding the constructor to call to create a managed NSObject instance in MSR #18358
• NativeAOT: Disable AggressiveAttributeTrimming with ILLink #18545
• NativeAOT: Do not root the framework assembly #18779

[ivanpovazan]

/cc: @simonrozsival

[ivanpovazan]

Closing as all the subtask have been completed. Thank you @simonrozsival!