Limit req/resp size and support stream bodies

[localvar]

This PR limits the request and response body size.
Support for stream bodies was also added, and several filters were refactored to aware of stream bodies.
Note that some features cannot use a stream body, as it can only be read once.

[codecov-commenter]

Codecov Report

Merging #628 (eb467a5) into pipeline (f9da7a3) will decrease coverage by 1.36%.
The diff coverage is 38.42%.

@@             Coverage Diff              @@
##           pipeline     #628      +/-   ##
============================================
- Coverage     73.57%   72.20%   -1.37%     
============================================
  Files            96       96              
  Lines         10611    10822     +211     
============================================
+ Hits           7807     7814       +7     
- Misses         2350     2528     +178     
- Partials        454      480      +26     

Impacted Files	Coverage Δ
pkg/filters/proxy/memorycache.go	96.20% <0.00%> (-3.80%)	⬇️
pkg/filters/proxy/proxy.go	83.90% <ø> (ø)
pkg/filters/responseadaptor/responseadaptor.go	33.92% <0.00%> (-2.27%)	⬇️
pkg/object/httpserver/spec.go	76.00% <ø> (ø)
pkg/protocols/httpprot/http.go	100.00% <ø> (ø)
pkg/util/readers/bytecountreader.go	0.00% <0.00%> (ø)
pkg/util/readers/callbackreader.go	0.00% <0.00%> (ø)
pkg/util/readers/gzipcompressreader.go	0.00% <0.00%> (ø)
pkg/protocols/httpprot/request.go	52.72% <25.64%> (-23.80%)	⬇️
pkg/protocols/httpprot/response.go	50.00% <26.66%> (-34.89%)	⬇️
... and 18 more

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