HHH-7990 - Bootstrapping Hibernate fails if javax.validation API is on classpath but no provider
(cherry picked from commit 898bab28ca63021b2f472f4f02608301154aebb1)

Conflicts:

	hibernate-core/src/main/java/org/hibernate/internal/CoreMessageLogger.java
HHH-8029 Improve SimpleNationalizedTest
HHH-8001 Temporarily disabled failing tests
HHH-7910 Transaction timeout can cause non-threadsafe session access by reaper thread