Add iterations to bulk edit on project and group

What does this MR do?

This MR allows a user with GitLab Starter license to bulk edit issues with iterations in the sidebar.

Dependent on backend MR !51179 (merged)

Repro

• Make sure you at least have a gitlab starter license
• Go to a project AND group issues list
• Bulk edit the issues, select one or more issues
• Then select an iteration in the dropdown

To confirm that the iteration has been applied, go to one of the issues that was selected in the bulk edit, and confirm the iteration appears in the sidebar. We have yet to add the iteration to the issues list item

Arch Decisions

• Given the sidebar has an existing pattern on bulk edit, i decided for MVC to mimic the existing approach, which invokes a full page refresh on form submission. This was discussed and confirmed with @pslaughter
• I created a new file, iterations_dropdown that simplifies the functionality of the approach for the iterations dropdown. In a follow up MR i will be replacing the dropdown in iterations_select with this component. I didnt do this here because it would have made the MR too large and get away from the core feature i was trying to accomplish, especially trying my best to make it into %13.8.

WIP

• FE Spec
• Making sure that licensed spec is being tested correctly

Relates to #196806 (closed)

Screenshots (strongly suggested)

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