This required working around internal ctor that uses internal (non
re-generated) types. E.g.
```
build/dotnet/maccatalyst/ref/Xamarin.iOS.cs(9201,64): error CS0234: The type or namespace name 'ABFunc<>' does not exist in the namespace 'AddressBookUI' (are you missing an assembly reference?)
```
We cannot just skip such constructor since the C# compiler will add a
**public** default one when none is present (and that's the case for
the error above),
This also required fixing the ctor chaining code (which can't be shared
with the, previously fixed, override code) so base classes could be
called for some `*EventArg` types.
Follow up to https://github.com/xamarin/xamarin-macios/pull/10658 , https://github.com/xamarin/xamarin-macios/pull/10678 and https://github.com/xamarin/xamarin-macios/pull/10706
This is the last framework that needs removal - but there's still a few
`unknown-*` entries in Catalyst-supported frameworks (more PR coming).
0f69381be8