LPS-49545 Added ANTLR grammar for LDAPFilter parsing based on RFC2254
LPS-49545 Added build target
LPS-49545 ANTLR generated
LPS-49545 Use LDAPFilterParser to validate LDAPFilter
LPS-49545 Fixed OmniAdmin login problem
LPS-49545 Validate SearchFilter on Search
LPS-49545 Added LDAPFilterValidator and LDAPFilterValidatorImpl to let it be accessible from service layer
LPS-49545 Moved LDAPUtilTest from portal-service to portal-impl as LDAPFilterValidator is needed to run this test. No Logical change
LPS-49545 Added extra test cases and fixed bad ones