Started testing and implementing search handler

Content ID criterion works as an example.
Make locations creatable by base test case
Tested & Implemted: Subtree criterion
Tested & Implemented: Location ID criterion
Tested & Implemented: Remote ID criterion
Tested & Implemented: Status criterion
Implemented & Tested: Logical criteria
Implemented & Tested: content type id criterion
Tested & Implemented: Parent location id creterium