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/fission-cli/flag/flag.go

@@ -74,6 +74,9 @@ var (
 
 	KubeContext = Flag{Type: String, Name: flagkey.KubeContext, Usage: "Kubernetes context to be used for the execution of Fission commands", DefaultValue: ""}
 
+	Labels     = Flag{Type: String, Name: flagkey.Labels, Usage: "Comma separated labels to apply to the function. Eg. --labels=\"environment=dev,application=analytics\""}
+	Annotation = Flag{Type: StringSlice, Name: flagkey.Annotation, Usage: "Annotation to apply to the function. To mention multiple annotations --annotation=\"abc.com/team=dev\" --annotation=\"foo=bar\""}
+
 	NamespaceFunction    = Flag{Type: String, Name: flagkey.NamespaceFunction, Aliases: []string{"fns"}, Usage: "Namespace for function object", DefaultValue: metav1.NamespaceDefault}
 	NamespaceEnvironment = Flag{Type: String, Name: flagkey.NamespaceEnvironment, Aliases: []string{"envns"}, Usage: "Namespace for environment object", DefaultValue: metav1.NamespaceDefault}
 	NamespacePackage     = Flag{Type: String, Name: flagkey.NamespacePackage, Aliases: []string{"pkgns"}, Usage: "Namespace for package object", DefaultValue: metav1.NamespaceDefault}

pkg/fission-cli/flag/key/key.go

@@ -26,6 +26,9 @@ const (
 	force        = "force"
 	Output       = "output"
 
+	Labels     = "labels"
+	Annotation = "annotation"
+
 	NamespaceFunction    = "fnNamespace"
 	NamespaceEnvironment = "envNamespace"
 	NamespacePackage     = "pkgNamespace"