Move "Move issue" to sidebar

What does this MR do?

• Add "Move issue" UI to right-sidebar
• Remove "Move issue" UI from /group/project/issues/x/edit
• Remove "Move issue" UI from inline issue edit

Are there points in the code the reviewer needs to double check?

EE MR, https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/2715

• Are we okay with using gl_dropdown?
  • Has all the right styles
  • Other sidebar dropdowns use it
• Usage of .js-sidebar-dropdown-toggle instead of .edit-link
  • See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13616#note_37946342

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

Closes #34261 (closed)