CODEOWNERS with list of maintainers

[stokito]

The second attempt of the #6830 that was closed after a discussion.
My proposition is to add the CODEOWNERS file to help for contributors to quickly find a maintainer (as I did myself today). Even better, for those devs that already have a write access they'll automatically be assigned as reviewers for a PR for the particular app.

The other steps like creating luci-dev team as I described in my comment can be done later. But the CODEOWNERS can start helping us today and save time for contributors. We may add a link to it into the PR template.

It won't change anything in terms of security so the PR is safe to merge.

[Ramon00]

just merge this?

[hnyman]

Not much has changed since #6830 which did not receive approval.
(and like jow noted in that PR, the proposed list already contains quite many ancient users who haven't been active for a while)

[stokito]

I'm not sure why that PR was closed. The discussion turned into enabling an automatic reviewer assignment. To enable this it needs to configure a team. Here I recreated the PR because even without this step this is just a list of github nicknames of maintainers. If some maintainer is not active anymore we can remove it from the list and from the package maintainer field. Anyway if someone creates a PR they'll find same persons and CC them. But we can simplify this step.

[Ramon00]

I guess this is in the catagory "better than nothing". But anyway, somebody needs to make decision, either merge or not. Waiting for the all singing and dancing solution will likely mean nothing will happen.