Add support for dynamic reverse proxy routing

[abhinavsingh]

Plugins must implement the def handle_route(self, request: HttpParser, pattern: re.Pattern[Any]) -> Url
method from the base class to provide a choice of upstream url to serve.

This work is backward compatible a.k.a. Old style static route patterns
with hardcoded upstream urls will continue to work as-is.

See ReverseProxyBasePlugin documentation for more details.

Fixes #1132

• Make it possible to have a dynamic reverse proxy #1132

[abhinavsingh]

@piraz @rpgmaster280 Please take a look at this PR. I have updated the example plugin with a dynamic route implementation. You'll need to write a plugin to handle your own custom dynamic routes. Best

[codecov]

Codecov Report

Merging #1180 (d90c58a) into develop (c3b966e) will decrease coverage by 0.09%.
The diff coverage is 68.25%.

❗ Current head d90c58a differs from pull request most recent head 7d68902. Consider uploading reports for the commit 7d68902 to get more accurate results

@@             Coverage Diff             @@
##           develop    #1180      +/-   ##
===========================================
- Coverage    87.24%   87.15%   -0.10%     
===========================================
  Files          166      166              
  Lines         6971     7012      +41     
  Branches       708      719      +11     
===========================================
+ Hits          6082     6111      +29     
- Misses         766      779      +13     
+ Partials       123      122       -1     

Flag	Coverage Δ
pytest	86.95% <65.07%> (-0.13%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
proxy/plugin/reverse_proxy.py	60.00% <55.55%> (-40.00%)	⬇️
proxy/http/server/reverse.py	83.07% <60.86%> (-9.79%)	⬇️
proxy/http/server/plugin.py	91.37% <80.00%> (-4.18%)	⬇️
proxy/common/types.py	100.00% <100.00%> (ø)
proxy/http/handler.py	76.10% <0.00%> (+0.88%)	⬆️
proxy/core/work/threadless.py	83.25% <0.00%> (+1.97%)	⬆️

📣 Codecov can now indicate which changes are the most critical in Pull Requests. Learn more