Add support for GitLab Draft/WIP MRs

Created by: eseliger

This contains the GitLab part of https://github.com/sourcegraph/sourcegraph/issues/7998.

• In the first commit, I implemented the events and state/history logic required to work for GitLab.
• In the second commit, I implemented the DraftChangesetSource on the GitLab client.
• In the third commit, some cleanup and fixes.

Tradeoff: There is no way to tell Update events apart, marking as WIP and unmarking do only trigger update events in the webhooks (which is fine I think).

Created by: codecov[bot]

Codecov Report

Merging #15004 into main will increase coverage by 0.00%. The diff coverage is 59.34%.

@@           Coverage Diff           @@
##             main   #15004   +/-   ##
=======================================
  Coverage   52.36%   52.36%           
=======================================
  Files        1556     1556           
  Lines       79548    79607   +59     
  Branches     7146     7146           
=======================================
+ Hits        41654    41685   +31     
- Misses      34149    34177   +28     
  Partials     3745     3745           

Flag	Coverage Δ		*Carryforward flag
#go	52.33% <59.34%> (+<0.01%)
#integration	30.41% <ø> (ø)		Carriedforward from 0fcea04
#storybook	25.82% <ø> (ø)		Carriedforward from 0fcea04
#typescript	52.44% <ø> (ø)		Carriedforward from 0fcea04
#unit	34.11% <ø> (ø)		Carriedforward from 0fcea04

*This pull request uses carry forward flags. Click here to find out more.

Impacted Files	Coverage Δ
internal/campaigns/changeset_event.go	0.00% <0.00%> (ø)
internal/campaigns/util.go	11.11% <ø> (ø)
cmd/repo-updater/repos/gitlab.go	77.12% <7.14%> (-3.96%)
internal/campaigns/changeset.go	49.86% <62.50%> (+<0.01%)
enterprise/internal/campaigns/changeset_history.go	84.49% <100.00%> (+1.44%)
enterprise/internal/campaigns/reconciler.go	61.44% <100.00%> (+0.47%)
enterprise/internal/campaigns/state.go	78.39% <100.00%> (+0.20%)
internal/extsvc/gitlab/merge_requests.go	70.00% <100.00%> (+3.33%)
internal/extsvc/gitlab/notes.go	85.18% <100.00%> (+2.57%)
internal/db/helpers.go	100.00% <0.00%> (ø)
... and 765 more

Created by: sourcegraph-bot

Notifying subscribers in CODENOTIFY files for diff 44004287a82809935a72a9ce76d2156900db4f11...a273a6b0f7a22e95e46b9a2309bc13eefb338c82.

Notify	File(s)
@LawnGnome	enterprise/internal/campaigns/changeset_history.go enterprise/internal/campaigns/counts_test.go enterprise/internal/campaigns/reconciler.go enterprise/internal/campaigns/state.go enterprise/internal/campaigns/state_test.go internal/campaigns/changeset.go internal/campaigns/changeset_event.go internal/campaigns/changeset_event_test.go internal/campaigns/util.go

Created by: sonarcloud[bot]

SonarCloud Quality Gate failed.

0 Bugs
0 Vulnerabilities (and 0 Security Hotspots to review)
6 Code Smells

No Coverage information
3.9% Duplication