Add delete image tag and delete image tag negative tests

*Updated delete image tag module to reflect cloud cafe changes
*Updated delete image tag negative module to reflect cloud cafe changes
*Updated modules aesthetic consistency
*Removed happy_path from test names
*Updated resource management of images to be used as queue
*Updated id to image_id for better readability
*Added verification for image tag addition and deletion throughout tests
*Added abstract method for verifying negative tests
*Deleted test_delete_tags module because tests are covered elsewhere
*Added validation for number_of_tags before deleting tags
*Removed test tags for testing purposes
*Removed invalid special characters test

Change-Id: I3537a0e19312c1696be395147347b640b4d46d6c
Merge "Add delete image tag and delete image tag negative tests"