Add labels to issues update mutation

What does this MR do?

Related to #208782 (closed)

This MR adds the arguments add_label_ids and remove_label_ids to the IssuesUpdate mutation to allow us to change labels in an issue.

These attributes are already being handled by IssuableBaseService when using Issues::UpdateService so it is sufficient with adding them as arguments to the mutation for it to work.

Similarly, We allow to update an epic's label by including these arguments in SharedEpicArguments.

Example query

mutation {
  updateIssue(input: {projectPath: "issue-reproduce/sub-group/test-project", iid: "1", removeLabelIds: [1480632], addLabelIds: [2098981, 2778788]}){
    issue{
      iid
      title
      dueDate
    }
    
  }
}

Screenshots

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