LPS-49545 Do not add extra brackets for LDAP search filters to avoid validation errors in some environments

Hi @migue,

As we discussed, I send you this PR because of ANTLR usage. I moved the test cases from portal-service to portal-impl, as I needed some portal-impl based classes in LDAPUtil, so it was impossible to call it from portal-service.  

As @marcellustavares already reviewed my former  PRs he if familiar with the problem and the LDAP related issues, so if you find it OK I think you can forward it to him.

Regards,
Vilmos