Instead of using routerCtx just escape the url before routing (#18086) (#18098)

Backport #18086

A consequence of forcibly setting the RoutePath to the escaped url is that the
auto routing to endpoints without terminal slashes fails (Causing #18060.) This
failure raises the possibility that forcibly setting the RoutePath causes other
unexpected behaviors too.

Therefore, instead we should simply pre-escape the URL in the process registering
handler. Then the request URL will be properly escaped for all the following calls.

Fix #17938
Fix #18060
Replace #18062
Replace #17997

Signed-off-by: Andrew Thornton <art27@cantab.net>

routers/common/middleware.go

@@ -22,6 +22,9 @@ func Middlewares() []func(http.Handler) http.Handler {
 	var handlers = []func(http.Handler) http.Handler{
 		func(next http.Handler) http.Handler {
 			return http.HandlerFunc(func(resp http.ResponseWriter, req *http.Request) {
+				// First of all escape the URL RawPath to ensure that all routing is done using a correctly escaped URL
+				req.URL.RawPath = req.URL.EscapedPath()
+
 				next.ServeHTTP(context.NewResponse(resp), req)
 			})
 		},