Update Test Helpers to use traits to set up mock security context and/or a mock db interface

### Tasks
- Create two new traits files in the TestHelpFolder, SecurityAwareTestCaseTrait and DbAdapterTestCaseTrait
- Move logic from AbstractSecurityAwareTestCase into SecurityAwareTestCaseTrait
- Update ControllerTestCase and MapperTestCase to use SecurityAwareTestCaseTrait and no longer inherit from AbstractSecurityAwareTestCase
- Remove AbstractSecurityAwareTestCase
- Move logic for setting up the mock db adapter from MapperTestCase into DbAdapterTestCaseTrait
- Update MapperTestCase to use DbAdapterTestCaseTrait