HHH-9071 When an already initialized proxy is narrowed, initialize the
new proxy (cherry picked from commit
2cf52cc7f1e1d8f918188d5166a3a869fc213cd8)

Conflicts:
	hibernate-core/src/main/java/org/hibernate/engine/internal/StatefulPersistenceContext.java
HHH-9071 - Proxy narrowing loses the initialized state of the original
proxy (cherry picked from commit
c5bdec20b96a1179d70338644d8c2d5f1408001e)

Conflicts:
	hibernate-core/src/main/java/org/hibernate/engine/internal/StatefulPersistenceContext.java