[vscode] support CommentThread state property

[rschnekenbu]

What it does

Add Comment#state optional property
This adds the state optional property from Comment to improve vscode api coverage. It also displays the state in the Comment Thread widget

Fixes #12231

Contributed on behalf of ST Microelectronics

How to test

Note: there are currently some issues with menus, since theia 1.28.0. This is due to #11290, integrated in 1.28.0. Prior to this change, the comment sample works on theia 1.27.0. So to test this change, I cherry-picked my commit on top of 1.27.0 tag.
This is the same case as for PR #12007.
The issue #12452 has been created to track those problems about menus.

1. Install forked extension #comment-sample-0.0.1 vsix file - Source
2. Create a comment using the side bar while comparing 2 test files and reply with some comment with toggle or reply.
   
3. The resolved state should be displayed along the thread label.

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[vince-fugnitto]

The code looks good, I unfortunately cannot really test due to the menu issues you presented.
@rschnekenbu you might want to enable the ability for maintainers to perform edits so we can update the branch as needed so it satisfies the "out-of-date" check.

[rschnekenbu]

@vince-fugnitto , thanks a lot for your review!

Still would it make sense to accept the PR? We could add a check on the issue #12452 for this API to be tested through the sample extension. The same should also be done for the already integrated Comment#timestamp property support.

And also, unfortunately, I can't switch this ability to perform edit on my own, despite being the creator of the PR. I don't have access to the configuration of the PR. We already tried with Thomas for previous PRs, as he wanted to be able to rebase my PRs on latest main.

[rschnekenbu]

I rebased on top of master and I fixed the minor comment.

[vince-fugnitto]

@rschnekenbu I think that’s fine, we can revisit and retest this pull-request once the menu is fixed, did I understand that you wanted to fix it?

[rschnekenbu]

@vince-fugnitto, I won't have time to fix the menu issue before next release unfortunately. I already did some investigation, but the refactoring introduced on #11290 was too complex for me to understand the root cause of the issue.
As for the comment timestamp, I would be in favor of pushing the PR. Indeed, the feature is working as expected on 1.27 and the changes are isolated. Along with #12453 & #12456, that would allow next theia release to be API compatible with vscode 1.77.

[vince-fugnitto]

Let's go ahead and keep #12452 in mind to properly review the changes once we fix the regression.

[rschnekenbu]

Thanks for the review, @vince-fugnitto!
I don't have the ability to merge (no write access). Can you merge it please?