[perf] Speed up type declaration rules by resolving reflection only when needed

[TomasVotruba]

Performance refactor of 4 rules. No behavior change - all fixtures pass unchanged.

Each rule did reflection or a subtree walk before a cheaper check could rule the node out:

• ReturnTypeFromStrictFluentReturnRector - the inferred return type is now checked for StaticType/ObjectType before resolveClassReflection(), so a method that does not return self/static/this never resolves the class reflection.
• ReturnTypeFromStrictTypedPropertyRector - the hasOnlyReturnWithExpr() shape check now runs before the per-return resolvePropertyReflectionFromPropertyFetch() loop.
• PropertyTypeFromStrictSetterGetterRector - the getter/setter type match (the rule's selective precondition) now runs before the isAssignedInConstructor() walk, so a property with no matching getter/setter skips the constructor scan.
• ChildDoctrineRepositoryClassTypeRector - the entity type is resolved from the @extends docblock, so a class with no doc comment bails before isObjectType().

Reordering is safe: all moved checks are side-effect-free bail conditions.