refactor: indicate progress during branch checkout

See merge request gitlab-org/gitlab-vscode-extension!299

feat: indicate which changed files have MR discussions

See merge request gitlab-org/gitlab-vscode-extension!298

feat(view issues-and-mrs): checkout local branch for merge request

See merge request gitlab-org/gitlab-vscode-extension!295

Credit: [@Musisimaru](https://gitlab.com/Musisimaru) (originally
    introduced in
    [!229](https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/merge_requests/229))

This is a copy paste of the code contributed by Mussimaru in
https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/merge_requests/229
This code doesn't compile, but I wanted to include it as a record that
he's done most of the work.

refactor: move discussion thread initialization to MrReviewItem

See merge request gitlab-org/gitlab-vscode-extension!296

chore: run `npm audit fix`

See merge request gitlab-org/gitlab-vscode-extension!297

refactor: create a separate interface for MR REST API response (RestMr)

See merge request gitlab-org/gitlab-vscode-extension!294

Credit: [@Musisimaru](https://gitlab.com/Musisimaru) (originally
introduced in
[!229](https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/merge_requests/229))

Credit: [@Musisimaru](https://gitlab.com/Musisimaru) (originally
introduced in
[!229](https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/merge_requests/229))

chore: specify that GitLab Workflow doesn't support remote workspaces

See merge request gitlab-org/gitlab-vscode-extension!291

chore: update node to 14.16.0

See merge request gitlab-org/gitlab-vscode-extension!289

fix: pipeline actions not working

See merge request gitlab-org/gitlab-vscode-extension!290

This reverts commit 058963f9.

The issue was caused by passing down wrong arguments to the api fetch
method.

This is the same version that VS Code uses starting from version 1.56.0

fix: prevent duplicate comments and comment controllers

See merge request gitlab-org/gitlab-vscode-extension!284

refactor: use semver for version comparison

See merge request gitlab-org/gitlab-vscode-extension!288

fix: minimum version check

See merge request gitlab-org/gitlab-vscode-extension!286

ci: Remove subject-case linting

See merge request gitlab-org/gitlab-vscode-extension!287

fix: temporarily disable version warning

See merge request gitlab-org/gitlab-vscode-extension!285

ci: commit-lint stricter footer policy

See merge request gitlab-org/gitlab-vscode-extension!279