feat(k8s/resource-pool): add the ability to mark/unmark resource pool as system (#5360)

* feat(k8s/resource-pool): add the ability to mark/unmark resource pool as system

fix(kube/ns): check label to see if namespace is system

refactor(k8s/namespaces): rename variables

feat(kubernetes): toggle system state in the server (#5361)

fix(app/resource-pool): UI fixes

feat(app/resource-pool): add confirmation modal when unamrking system namespace

* refactor(app): review changes

* feat(app/namespaces): introduce store to retrieve namespace system status without changing all the kubernetes models

refactor(app/namespaces): remove unused code first introduced for system tagging

fix(app/namespaces): cache namespaces to retrieve system status regardless of namespace reference format

refactor(app): migrate namespace store from helper to a separate singleton

refactor(app): remove KubernetesNamespaceHelper from DI cycle

* refactor(app): normalize usage of KubernetesNamespaceHelper functions

* refactor(app/k8s): change namespace store to functions instead of class

Co-authored-by: LP B <xAt0mZ@users.noreply.github.com>

api/http/middlewares/endpoint.go

@@ -0,0 +1,58 @@
+package middlewares
+
+import (
+	"context"
+	"errors"
+	"net/http"
+
+	"github.com/gorilla/mux"
+	httperror "github.com/portainer/libhttp/error"
+	requesthelpers "github.com/portainer/libhttp/request"
+	portainer "github.com/portainer/portainer/api"
+	bolterrors "github.com/portainer/portainer/api/bolt/errors"
+)
+
+const (
+	contextEndpoint = "endpoint"
+)
+
+func WithEndpoint(endpointService portainer.EndpointService, endpointIDParam string) mux.MiddlewareFunc {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(rw http.ResponseWriter, request *http.Request) {
+			if endpointIDParam == "" {
+				endpointIDParam = "id"
+			}
+
+			endpointID, err := requesthelpers.RetrieveNumericRouteVariableValue(request, endpointIDParam)
+			if err != nil {
+				httperror.WriteError(rw, http.StatusBadRequest, "Invalid endpoint identifier route variable", err)
+				return
+			}
+
+			endpoint, err := endpointService.Endpoint(portainer.EndpointID(endpointID))
+			if err != nil {
+				statusCode := http.StatusInternalServerError
+
+				if err == bolterrors.ErrObjectNotFound {
+					statusCode = http.StatusNotFound
+				}
+				httperror.WriteError(rw, statusCode, "Unable to find an endpoint with the specified identifier inside the database", err)
+				return
+			}
+
+			ctx := context.WithValue(request.Context(), contextEndpoint, endpoint)
+
+			next.ServeHTTP(rw, request.WithContext(ctx))
+
+		})
+	}
+}
+
+func FetchEndpoint(request *http.Request) (*portainer.Endpoint, error) {
+	contextData := request.Context().Value(contextEndpoint)
+	if contextData == nil {
+		return nil, errors.New("Unable to find endpoint data in request context")
+	}
+
+	return contextData.(*portainer.Endpoint), nil
+}