Fix signature badge on commits tab of merge request

What does this MR do?

On the 'Commits' view of a repository, a signature badge (Verified or Unverified) is displayed for each signed commit (e.g. see http://localhost:3000/gitlab-org/gitlab-test/-/commits/feature). The same is actually implemented for the 'Commits' tab on the view of a merge request. But in this case, the raw data and thus the signature of the commit is not loaded, so no signature badge is displayed (e.g. see http://localhost:3000/gitlab-org/gitlab-test/-/merge_requests/8/commits).

This MR fixes the described ~bug: By a change when loading the commits, the signature badges are also displayed in the 'Commits' tab on the view of a merge request.

🛠 with ❤ at Siemens

/cc @bufferoverflow

Screenshots

http://localhost:3000/gitlab-org/gitlab-test/-/merge_requests/8/commits:

Before	After

How to setup and validate locally

1. Visit a 'Commits' view of a repository with signed commits such as http://localhost:3000/gitlab-org/gitlab-test/-/commits/feature
2. Check: A signature badge (Verified or Unverified) is displayed for each signed commit. This is how it should be.
3. Visit the 'Commits' tab of a merge request containing the same commits as above such as http://localhost:3000/gitlab-org/gitlab-test/-/merge_requests/8/commits
4. Check: No signature badges are displayed even for signed commits.
5. Apply the changes of this MR and refresh the page.
6. Check: Now, a signature badge is displayed for each signed commit.

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• I have tested this MR in all supported browsers, or it's not needed.
• I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

Security

Does this MR contain changes to processing or storing of credentials or tokens, authorization and authentication methods or other items described in the security review guidelines? If not, then delete this Security section.

• [-] 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