Feat/fileserver (#60)

* cleanup code for URL type

* fix makefile for trace mode

* refactor, merge Entry, RawEntry and Route into one. 

* Implement fileserver.

* refactor: rename HTTPRoute to ReverseProxyRoute to avoid confusion

* refactor: move metrics logger to middleware package

- fix prometheus metrics for load balanced routes
  - route will now fail when health monitor fail to start

* fix extra output of ls-* commands by defer initializaing stuff, speed up start time

* add test for path traversal attack, small fix on FileServer.Start method

* rename rule.on.bypass to pass

* refactor and fixed map-to-map  deserialization

* updated route loading logic

* schemas: add "add_prefix" option to modify_request middleware


* updated route JSONMarshalling

---------

Co-authored-by: yusing <yusing@6uo.me>

internal/route/rules/on_test.go

@@ -212,7 +212,7 @@ func TestOnCorrectness(t *testing.T) {
 		},
 		{
 			name:    "basic_auth_correct",
-			checker: "basic_auth user " + string(E.Must(bcrypt.GenerateFromPassword([]byte("password"), bcrypt.DefaultCost))),
+			checker: "basic_auth user " + string(Must(bcrypt.GenerateFromPassword([]byte("password"), bcrypt.DefaultCost))),
 			input: &http.Request{
 				Header: http.Header{
 					"Authorization": {"Basic " + base64.StdEncoding.EncodeToString([]byte("user:password"))}, // "user:password"
@@ -222,7 +222,7 @@ func TestOnCorrectness(t *testing.T) {
 		},
 		{
 			name:    "basic_auth_incorrect",
-			checker: "basic_auth user " + string(E.Must(bcrypt.GenerateFromPassword([]byte("password"), bcrypt.DefaultCost))),
+			checker: "basic_auth user " + string(Must(bcrypt.GenerateFromPassword([]byte("password"), bcrypt.DefaultCost))),
 			input: &http.Request{
 				Header: http.Header{
 					"Authorization": {"Basic " + base64.StdEncoding.EncodeToString([]byte("user:incorrect"))}, // "user:wrong"