Add /lock and /unlock quick actions

What does this MR do?

It adds support for /lock and /unlock quick actions

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

Worth adding feature specs? I don't see feature specs for all the quick actions, only some.

Why was this MR needed?

Closes #39173 (closed)

Screenshots (if relevant)

With a user with the ability to admin the issue (he can lock/unlock)

He sees the command suggested, and it's applied.

With a user without the ability to admin the issue (he can not lock/unlock)

He doesn't see the command suggested, and it's not applied.

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
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

#39173 (closed)