Support quick actions when editing an issue / MR / epic description
Summary
We already support quick actions when editing comments (added in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/31136).
We should also support quick actions when editing descriptions.
This is very useful in cases where you need to apply a template after an issue / MR / epic is created.
Some cases where a user needs to edit:
- Creating an issue from the issue board only allows setting of title.
- Creating an epic also only has the title field.
- Creating an MR from git push options
Steps to reproduce
- Create a template that contains
/label - Create a new issue with the template, and notice that
/labelis stripped - Create a new issue without a template, say from a board
- Edit the issue, assign the template, and save
- notice that
/labelis not stripped
Expected behavior
/label should apply the label and be stripped.
Actual behavior
/label appears in the issue.
Relevant logs and/or screenshots
