Automatically open discussions in MRs if there are TODOs in the sourcecode changeset

Release notes

Provide a possibility to automatically open discussions in MRs if there are TODOs in the sourcecode

Problem to solve

We often place TODOs in our sourcecode to remind us for reviews or for merges:

to remove debug or temporary testing code before merging
to start a discussion for a non-obvious detail of the implementation
to mark a certain part of the implementation when performing reviews directly on sourcecode checkout
request the input of a team member

It would be great to have the possibility to automatically open a review comment thread for that in the MR.

Proposal

Provide the possibility to configure a review marker keyword for projects as a regex (i.e. "\s+TODO\s*:") Automatically open discussion threads in the merge request if that keyword is discovered in the changeset of the merge requests.

Intended users

Who will use this feature? If known, include any of the following: types of users (e.g. Developer), personas, or specific company roles (e.g. Release Manager). It's okay to write "Unknown" and fill this field in later.

Personas are described at https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/

User experience goal

What is the single user experience workflow this problem addresses? For example, "The user should be able to use the UI/API/.gitlab-ci.yml with GitLab to " https://about.gitlab.com/handbook/engineering/ux/ux-research-training/user-story-mapping/

Further details

Include use cases, benefits, goals, or any other details that will help us understand the problem better.