Quick action /relate doesn't work when creating an issue

Summary

/relate works when posting an issue comment, but when creating an issue, it does not work in the description.

Steps to reproduce

• Create an issue and try to use /relate quick action

What is the current bug behavior?

• The line for /relate is completely ignored

What is the expected correct behavior?

• It should mark the target issue as related, as used in a comment.

Relevant logs and/or screenshots

This affects gitlab-qa#620 (closed)

Output of checks

This bug happens on GitLab.com

Possible fixes

• We have to split quick actions into 2 parts and ones to be performed before save and ones to be performed after save. So far we always perform them before save so some quick actions cannot be performed, therefore simply discarded.