chore: add apisixconsumer data structures

[tokers]

Please answer these questions before submitting a pull request

This Pull Request adds the basic CRD and go struct data structures.

• Why submit this pull request?

• Bugfix

• New feature provided

• Improve performance

• Backport patches

• Related issues

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Bugfix

• Description

• How to fix?

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New feature or improvement

• Describe the details and related test reports.

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Backport patches

• Why need to backport?

• Source branch

• Related commits and pull requests

• Target branch

[codecov-commenter]

Codecov Report

Merging #462 (cb98a20) into master (015940c) will decrease coverage by 0.05%.
The diff coverage is 0.00%.

❗ Current head cb98a20 differs from pull request most recent head 1ccd4f6. Consider uploading reports for the commit 1ccd4f6 to get more accurate results

@@            Coverage Diff             @@
##           master     #462      +/-   ##
==========================================
- Coverage   37.04%   36.99%   -0.06%     
==========================================
  Files          47       46       -1     
  Lines        3841     3844       +3     
==========================================
- Hits         1423     1422       -1     
- Misses       2233     2237       +4     
  Partials      185      185              

Impacted Files	Coverage Δ
pkg/apisix/cluster.go	26.69% <0.00%> (-0.35%)	⬇️
pkg/ingress/controller.go	0.00% <0.00%> (ø)
pkg/ingress/endpoint.go	0.00% <0.00%> (ø)
test/e2e/e2e.go

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[tokers]

@gxthrj Please look it again.