Labels and annotation support for functions and environments (#2113)

1. Support for adding labels and annotations to functions & environment via fission CLI through create & update command.
2. Change ensures labels and annotations assigned to the environment would reflect on pods created via executor type pool manager and new deploy.

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

pkg/utils/maps/map.go

@@ -0,0 +1,24 @@
+/*
+Copyright 2021 The Fission Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+package maps
+
+func CopyStringMap(m map[string]string) map[string]string {
+	n := make(map[string]string)
+	for k, v := range m {
+		n[k] = v
+	}
+	return n
+}