Fix coding standards in database schemes. Use DbAdapterFactory in all unit
tests instead of creating own adapters. Fix DbUserBackend and DbStore to use
FETCH_OBJ, instead of FETCH_ASSOC, to handle it consistently in the whole
application. Remove unnecessary table columns from the "account" scheme.
refs #4577
refs #4578
refs #4596
refs #4599
refs #4627
Change the StoreFactory configuration to reference to a resource instead of
defining the whole database. Additionally fix docstrings, fix imports and fix
function calls to comply to coding style standards.
refs #4503