[Mono] Implement mono_weak_hash_table_lookup_extended

[fanyang-mono]

... also use it inreflection-cache.h in the collectible ALC case

Refer to https://github.com/dotnet/runtime/pull/85796/files#r1188676484

[fanyang-mono]

This is a new functionality that we would like to add. But I won't be able to get to it within .NET8. Moving to 9.0.0

[fanyang-mono]

Can't get to it in .NET8. Moving to 9.0.0