refactor: Nullable and Modernization for Stride.Core.Serialization

[IXLLEGACYIXL]

PR Details

Modernizing Stride.Core.Reflection

Description

1. Should enable Nullable instead of Strides NotNull attribute
2. Should reduce the usage of reflection, mainly used in collection Descriptors ( thats now prototyped for Dictionary, if its in interested i can convert set and list and the others too )
3. Using new C# features ie collection initialization, Pattern Matching etc

Related Issue

#2156
#2155
Removes all [NotNull] annotations and uses the new Nullable
Removes a bug taht System.Collections anyway crash the editor as serializers are missing

Motivation and Context

Types of changes

• Docs change / refactoring / dependency upgrade ( some comments changed )
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have built and run the editor to try this change out.

[IXLLEGACYIXL]

would be ready for review

dont know what oldcollection descriptor does to be still required

some nullable warnings are still existent but i dont know how to resolve them

[Eideren]

Looks great, thanks a bunch for your work @IXLLEGACYIXL

[IXLLEGACYIXL]

ran tests and they fail currently, maybe its a compilation issue... lets see..

[IXLLEGACYIXL]

WELL sample tests fail but on all branches with latest main, but the descriptor tests and all other engien tests pass so it seems good

[Eideren]

Yep, it's good, TC reported 4 failing tests but those are unrelated, see #2296

[Eideren]

Thanks !