Refactor organization of scope aware request utils

Reorganized the structure of the Request Utils due to their widespread use
resulting in circular imports issues (mostly because of middleware & logger).

pkg/apis/middleware/scope.go

@@ -1,9 +1,18 @@
 package middleware
 
 import (
+	"context"
+	"net/http"
+
 	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/apis/sessions"
 )
 
+type scopeKey string
+
+// RequestScopeKey uses a typed string to reduce likelihood of clashing
+// with other context keys
+const RequestScopeKey scopeKey = "request-scope"
+
 // RequestScope contains information regarding the request that is being made.
 // The RequestScope is used to pass information between different middlewares
 // within the chain.
@@ -26,3 +35,19 @@ type RequestScope struct {
 	// it was loaded or not.
 	SessionRevalidated bool
 }
+
+// GetRequestScope returns the current request scope from the given request
+func GetRequestScope(req *http.Request) *RequestScope {
+	scope := req.Context().Value(RequestScopeKey)
+	if scope == nil {
+		return nil
+	}
+
+	return scope.(*RequestScope)
+}
+
+// AddRequestScope adds a RequestScope to a request
+func AddRequestScope(req *http.Request, scope *RequestScope) *http.Request {
+	ctx := context.WithValue(req.Context(), RequestScopeKey, scope)
+	return req.WithContext(ctx)
+}