Restructured authmiddleware fn and added tests (#2410)

* Created separate file for authmiddleware fn
* Optimize auth login and middleware
* Added unittests for authmiddleware
* Fixed authURL
* Removed featureConfig as global variable
* Fix integration test according to examples repo changes
* Fix integration test path for go module-example

Co-authored-by: Sanket Sudake <sanketsudake@gmail.com>

pkg/router/router.go

@@ -70,7 +70,7 @@ import (
 func router(ctx context.Context, logger *zap.Logger, httpTriggerSet *HTTPTriggerSet) *mutableRouter {
 	var mr *mutableRouter
 	mux := mux.NewRouter()
-	mux.Use(metrics.HTTPMetricMiddleware())
+	mux.Use(metrics.HTTPMetricMiddleware)
 
 	// see issue https://github.com/fission/fission/issues/1317
 	useEncodedPath, _ := strconv.ParseBool(os.Getenv("USE_ENCODED_PATH"))