This prevents confusion between GitLab project and VS Code workspace.
The current legacy naming that uses the name "project" to represent
VS Code workspace is diverging from an established naming and
confuses contributors.

The work "project" is used throughout the codebase for GitLab project
and it was causing confusion when two variables named 'project' meant
different things.

All logic related to creating vscode.CommentThread and
setting the correct properties has been extracted to one class.

This class will be responsible for resolving threads in the future.

The GitLabComment is going to be responsible for all comment-related
functionality like editing, deleting and reacting.

this limits the blast radius of existing GitLab issue
https://gitlab.com/gitlab-org/gitlab/-/issues/298827

This change starts fetching position for each discussion and then
it displays the discussions on diffs using the native VS Code API