Normalize function for String order criteria in SQL2 as well

In JCR-3443, a normalize function was provided for String order criteria of XPath queries.

Doing the same for SQL2 requires extension of the Query Object Model, as described in https://issues.apache.org/jira/browse/JCR-3443?focusedCommentId=13579073&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13579073:

The problem is that Xpath and SQL1 is based on an extensible grammar : is was quite easy to extend it to add a new function.
SQL2 is technically based on the QueryObjectModelFactory, which offer one method per function. We then have to extend the Java API to add a new function.
We may add a JackrabbitQueryObjectModelFactory extending the JCR one with new methods...