chore(refactor): the translation of upstream

[AlinsRan]

Type of change:

• Bugfix
• New feature provided
• Improve performance
• Backport patches

What this PR does / why we need it:

Backend: The code logic of this part is split into many places, and there is redundancy.

• Decouple the translation of upstream, the logic of this part only exists in one place.
• Delete redundant codes.

Pre-submission checklist:

• Did you explain what problem does this PR solve? Or what new features have been added?
• Have you added corresponding test cases?
• Have you modified the corresponding document?
• Is this PR backward compatible? If it is not backward compatible, please discuss on the mailing list first

[codecov-commenter]

Codecov Report

❌ Patch coverage is 15.67164% with 113 lines in your changes missing coverage. Please review.
✅ Project coverage is 41.35%. Comparing base (f71b376) to head (23fe9e6).
⚠️ Report is 415 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/providers/translation/upstream.go	14.70%	56 Missing and 2 partials ⚠️
pkg/providers/ingress/translation/translator.go	0.00%	32 Missing ⚠️
pkg/providers/apisix/translation/apisix_route.go	20.83%	18 Missing and 1 partial ⚠️
pkg/providers/translation/apisix_upstream.go	57.14%	3 Missing ⚠️
.../providers/gateway/translation/gateway_tlsroute.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1295      +/-   ##
==========================================
+ Coverage   40.62%   41.35%   +0.73%     
==========================================
  Files          75       75              
  Lines        7006     6771     -235     
==========================================
- Hits         2846     2800      -46     
+ Misses       3847     3657     -190     
- Partials      313      314       +1     

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[tao12345666333]

could you please resolve conflicts? thanks

[tao12345666333]

Sorry for delay.
There are too many conflicts now. If you want to proceed, you need to resolve the conflict first. thanks

[tao12345666333]

Since there are tons of conflicts and no updates yet, I want to put it in v1.7. thanks