fixes serviceApi search function AND/OR operators

- search function parses both AND and OR operators (OOIION-1522)
- aborts with descriptive 400 error if query includes both AND and OR, user may only use one (OOIION-1522)
- added description to error returned by all fields blank in advanced search (OOIION-1413, commented on by Bill B in OOIION-1208)

fixes OOIION-1522
addresses comments on OOIION-1413 (comment left by Bill B in OOIION-1208)