ContainerRegistry: adjust query and mutation names

What does this MR do?

As @oregand pointed out here: !49703 (comment 464942558) it seems that the container registry was not following the proper convention for query and mutation names!

This MR fixes this, by renaming query and mutations, it also addressed an issue where the group query had the same internal name as the project one, making the debug of them a bit harder!

Screenshots (strongly suggested)

No visual changes

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team