Fixing various AOT bugs

[manodasanW]

• Fixed issue where nested types were not correctly represented in the lookup table with a +.
• Fixed issue where multi-level generic types were not correctly represented in the lookup table where the generics need to come at the end after all the nested generic types
• Fix issue where ObservableCollection's use of SingleItemReadOnlyList causes interface not found issues due to the latter type is an internal type within the .NET runtime and thereby the source generator not being able to run on it. Special casing to handle that if ObservableCollection is found to be used.
• Fix typo with IMapChangedEventArgs
• Fix issue where for KeyValuePair, we didn't do a proper WinRT type check before generating the vtable causing issues with withing ABI functions not being there due to they are not expected to be there.

Fixes #1638
Fixes #1631
Fixes microsoft/microsoft-ui-xaml#9699
Fixes microsoft/microsoft-ui-xaml#9710