HHH-19034 Fix use of findCompatibleFetchJoin

The problem was that you had a different SQL query
depending on the order the fetch and join operations were
created when defining a criteria query.

For example:
```
// Example 1:
Root<Book> from = criteriaQuery.from( Book.class );
Fetch<Object, Object> fetch = from.fetch( "authors" );
Join<Object, Object> join = from.join( "authors" );
```
it was different than
```
// Example 2:
Root<Book> from = criteriaQuery.from( Book.class );
Join<Object, Object> join = from.join( "authors" );
Fetch<Object, Object> fetch = from.fetch( "authors" );
```

In the first example, `fetch` and `join` were exactly the
same object, causing issues if the association `authors` appeared
in the `where` clause. For example:
```
criteriaQuery.where( cb.equal( join.get( "id" ), 2L ) );
```

Note that now we always rung an extra join even when not necessary.
But this is consistent with what happen with HQL, and we can figure
out how to add this improvement in a different issue.

Author: DavideD

hibernate-core/src/main/java/org/hibernate/query/sqm/tree/domain/AbstractSqmFrom.java

@@ -793,9 +793,11 @@ private <A> SqmAttributeJoin<T, A> buildJoin(
 			SqmPathSource<A> joinedPathSource,
 			SqmJoinType joinType,
 			boolean fetched) {
-		final SqmAttributeJoin<T, A> compatibleFetchJoin = findCompatibleFetchJoin( this, joinedPathSource, joinType );
-		if ( compatibleFetchJoin != null ) {
-			return compatibleFetchJoin;
+		if ( fetched ) {
+			final SqmAttributeJoin<T, A> compatibleFetchJoin = findCompatibleFetchJoin( this, joinedPathSource, joinType );
+			if ( compatibleFetchJoin != null ) {
+				return compatibleFetchJoin;
+			}
 		}
 
 		final SqmAttributeJoin<T, A> sqmJoin;