feat: remove the etcd dependency in the service unit test

[starsz]

Please answer these questions before submitting a pull request

• Why submit this pull request?

• [] Bugfix

• New feature provided

• Improve performance

• Related issues

#1161

New feature or improvement

• Describe the details and related test reports.

Remove the etcd dependency in the service unit test

[codecov-io]

Codecov Report

Merging #1169 (f8239e2) into master (9824b5f) will decrease coverage by 10.14%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master    #1169       +/-   ##
===========================================
- Coverage   67.08%   56.93%   -10.15%     
===========================================
  Files          46       46               
  Lines        2947     2947               
===========================================
- Hits         1977     1678      -299     
- Misses        731     1004      +273     
- Partials      239      265       +26     

Impacted Files	Coverage Δ
api/internal/handler/plugin/plugin.go	16.66% <0.00%> (-70.00%)	⬇️
api/internal/core/store/query.go	45.23% <0.00%> (-52.39%)	⬇️
api/internal/core/store/selector.go	35.18% <0.00%> (-51.86%)	⬇️
api/internal/core/store/validate_mock.go	0.00% <0.00%> (-50.00%)	⬇️
api/internal/filter/authentication.go	44.11% <0.00%> (-32.36%)	⬇️
api/internal/core/store/store.go	56.96% <0.00%> (-29.70%)	⬇️
api/internal/handler/global_rule/global_rule.go	64.51% <0.00%> (-19.36%)	⬇️
api/internal/handler/consumer/consumer.go	74.46% <0.00%> (-17.03%)	⬇️
api/internal/handler/ssl/ssl.go	33.33% <0.00%> (-14.82%)	⬇️
api/internal/utils/json_patch.go	44.82% <0.00%> (-13.80%)	⬇️
... and 14 more

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[juzhiyuan]

@starsz you need to request members to review.

[juzhiyuan]

waiting for #1426

[juzhiyuan]

@starsz You may need to request reviews from others first.

[juzhiyuan]

may sync the latest codes to fix E2E failed.

[imjoey]

/lgtm

Nice PR and will make writing backend unit test more convenient. Thanks @starsz .