Allow idiomatic usage of middlewares in gorilla/mux (#9802)

Historically due to lack of support for middlewares
we ended up writing wrapped handlers for all
middlewares on top of the gorilla/mux, this causes
multiple issues when we want to let's say

- Overload r.Body with some custom implementation
  to track the incoming Reads()
- Add other sort of top level checks to avoid
  DDOSing the server with large incoming HTTP
  bodies.

Since 1.7.x release gorilla/mux provides proper
use of middlewares, which are honored by the muxer
directly. This makes sure that Go can honor its
own internal ServeHTTP(w, r) implementation where
Go net/http can wrap into its own customer readers.

This PR as a side-affect fixes rare issues of client
hangs which were reported in the wild but never really
understood or fixed in our codebase.

Fixes #9759
Fixes #7266
Fixes #6540
Fixes #5455
Fixes #5150

Refer https://github.com/boto/botocore/pull/1328 for
one variation of the same issue in #9759

cmd/generic-handlers.go

@@ -34,14 +34,14 @@ import (
 	"github.com/rs/cors"
 )
 
-// HandlerFunc - useful to chain different middleware http.Handler
-type HandlerFunc func(http.Handler) http.Handler
+// MiddlewareFunc - useful to chain different http.Handler middlewares
+type MiddlewareFunc func(http.Handler) http.Handler
 
-func registerHandlers(h http.Handler, handlerFns ...HandlerFunc) http.Handler {
-	for _, hFn := range handlerFns {
-		h = hFn(h)
+func registerMiddlewares(next http.Handler) http.Handler {
+	for _, handlerFn := range globalHandlers {
+		next = handlerFn(next)
 	}
-	return h
+	return next
 }
 
 // Adds limiting body size middleware
@@ -795,6 +795,7 @@ func (h criticalErrorHandler) ServeHTTP(w http.ResponseWriter, r *http.Request)
 	defer func() {
 		if err := recover(); err == logger.ErrCritical { // handle
 			writeErrorResponse(r.Context(), w, errorCodes.ToAPIErr(ErrInternalError), r.URL, guessIsBrowserReq(r))
+			return
 		} else if err != nil {
 			panic(err) // forward other panic calls
 		}