[TypeDeclaration] Add AddClosureReturnTypeFromReturnCastRector

[samsonasik]

Part of resolve this issue effort:

• [DX] Allow more granulated return type completion, to separate from closures and makes easier to review rector#8678

Ref from PR comment:

• [TypeDeclaration] Separate Closure return type #6029 (comment)

this PR extract Closure from ReturnTypeFromReturnCastRector into separate new rule: AddClosureReturnTypeFromReturnCastRector special for Closure only.

[samsonasik]

All checks have passed 🎉 @TomasVotruba it is ready for review.

[TomasVotruba]

Thank you 👍