feature: add etcd distributed lock

[littlejiancc]

What type of this PR

/kind feature

What this PR does / why we need it:

feature: add etcd distributed lock

Which issue(s) this PR fixes:

gittar单点问题修复

• Fixes #your-issue_number
• [Erda Cloud Issue Link](paste your link here)

Specified Reviewers:

/assign @sfwn

ChangeLog

Language	Changelog
🇺🇸 English	add etcd distributed lock
🇨🇳 中文	增加etcd分布式锁

Need cherry-pick to release versions?

Add comment like /cherry-pick release/1.0 when this PR is merged.

For details on the cherry pick process, see the cherry pick requests section under CONTRIBUTING.md.

[codecov]

Codecov Report

Merging #1548 (d723b67) into master (994ad9f) will increase coverage by 0.02%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #1548      +/-   ##
==========================================
+ Coverage   13.28%   13.30%   +0.02%     
==========================================
  Files        1078     1083       +5     
  Lines      111326   111751     +425     
==========================================
+ Hits        14786    14873      +87     
- Misses      95174    95477     +303     
- Partials     1366     1401      +35     

Impacted Files	Coverage Δ
modules/gittar/pkg/gitmodule/repo.go	0.00% <ø> (ø)
modules/gittar/pkg/gitmodule/repo_edit.go	5.12% <0.00%> (-0.66%)	⬇️
...omponents/issue-manage/issueKanban/issue_kanban.go	0.15% <0.00%> (-0.01%)	⬇️
modules/dop/endpoints/endpoints.go	0.55% <0.00%> (-0.01%)	⬇️
apistructs/audits.go	0.00% <0.00%> (ø)
apistructs/runtime.go	0.00% <0.00%> (ø)
modules/orchestrator/endpoints/runtime.go	0.00% <0.00%> (ø)
...ocol/components/issue-manage/issueFilter/render.go	0.00% <0.00%> (ø)
...ocol/components/issue-manage/issueKanban/render.go	0.00% <0.00%> (ø)
... and 14 more

[sfwn]

You have to add some unit test for this patch.

[sfwn]

• fix patch coverage
• add a Sequence Diagram to describe currency external repo ops

[sfwn]

/approve