Repositories to handle new checksum-type attribute.

Updated locators, factory, repository modules for the support.
Updated the CRUD functions for the support.

Also added two new tests `test_create_repo_5` and
`test_positive_update_3` to the `ui/test_repository` module.
Merge pull request #1584 from kbidarkar/add-checksum-support

Repositories to handle new checksum-type attribute.