Fix: Should not be possible to add action item within new issue description

Currently, it is possible to type `/` in a new issue description and select `Action item` from the dropdown menu. Selecting `Action item` does nothing and should be removed from the menu as an option.

> On one hand, we cannot create todos (action items) until the issue is created, because it can remain in draft or user can close the dialog without creating the issue.
>
> On the other hand, if I want to add an action item to the issue description, I would like to be able to do it here as well, otherwise I will have to modify description after the issue is created.


_{Huly®: UBERF-8255}