feat: add rewrite:RespHeaders and modify the upstream response ers via request implementation

[rampagecong]

This submission is modified as follows:

1.Add respHdr and RespHeader method to Request struct.

2.The Request FetchChanges method is modified.

3.Add and modify some test cases

This is refer to #67

[spacewander]

Sorry for my delay. Could you make the CI pass?

[spacewander]

Need to update go.mod to use github.com/api7/ext-plugin-proto v0.4.0

[rampagecong]

OK

[spacewander]

Need to resolve conflicts

[codecov-commenter]

Codecov Report

Merging #68 (24381ca) into master (ade2e90) will decrease coverage by 2.19%.
The diff coverage is 96.15%.

❗ Current head 24381ca differs from pull request most recent head 95a790f. Consider uploading reports for the commit 95a790f to get more accurate results

@@            Coverage Diff             @@
##           master      #68      +/-   ##
==========================================
- Coverage   80.60%   78.41%   -2.20%     
==========================================
  Files          11       11              
  Lines         722      746      +24     
==========================================
+ Hits          582      585       +3     
- Misses        102      122      +20     
- Partials       38       39       +1     

Impacted Files	Coverage Δ
internal/http/request.go	93.49% <96.15%> (+0.70%)	⬆️
internal/server/server.go	50.40% <0.00%> (-17.08%)	⬇️

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[rampagecong]

Hello,Please run CI again.
@spacewander