Extracting configuration related logic came up in reviews multiple times.
Also, the VS Code logic returns missing properties as null.
This behaviour is not ideal because null function arguments overrdie the
default function arguments.

Related discussions:
- https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/merge_requests/115#note_432956679

This fixes a minor bug where if user hasn't configured their
instaenceUrl (presumably they use the default gitlab.com),
the webview is going to put `null` in the links. This fix
makes sure we use the same logic as the rest of the app.

test: increase integration test timeout

See merge request gitlab-org/gitlab-vscode-extension!184

refactor(status bar): extract status_bar module into a class

See merge request gitlab-org/gitlab-vscode-extension!181

test(integration): reduce test flakiness by replacing globalState

See merge request gitlab-org/gitlab-vscode-extension!180

test(for_current_branch): fix hardcoded date breaking tests

See merge request gitlab-org/gitlab-vscode-extension!179

fix: support displaying users without avatars

See merge request gitlab-org/gitlab-vscode-extension!178

Update GitLab CI variables (used for autocompletion) + add docs

See merge request gitlab-org/gitlab-vscode-extension!177

fix(sidebar): log error when fetching items

See merge request gitlab-org/gitlab-vscode-extension!175

This rule is critical. We must have a guarantee that when there is
a try/catch around a return statement, we will catch the error.

test(user agent): fix broken user-agent test

See merge request gitlab-org/gitlab-vscode-extension!176

fix(side tree): for current branch not working for multiroot projects

See merge request gitlab-org/gitlab-vscode-extension!174

feat: try to get MR diff conent from local git before fetching from API

See merge request gitlab-org/gitlab-vscode-extension!173

This is an optimisation where we check the local git repository
and only when the file in given version doesn't exist there
we'll call the GitLab API to retrieve the file content.

docs: merge request reviews feature documentation

See merge request gitlab-org/gitlab-vscode-extension!170

refactor(gitlab_project): fetch project.webUrl to fix openers

See merge request gitlab-org/gitlab-vscode-extension!171

fix(git_service): throw errors when git command fails, don't return null

See merge request gitlab-org/gitlab-vscode-extension!169

This is the first step in not swallowing critical errors deep in
the GitService. It allows us to follow the error path for each
public function separately.

Merge branch '275-api-request-failed-when-trying-to-get-current-project-because-error-404-project-not-found' into 'main'

fix(gitlab-service): do not fail if project could not be found

See merge request gitlab-org/gitlab-vscode-extension!130

fix(gitlab_service): include request URL when logging error

See merge request gitlab-org/gitlab-vscode-extension!167