Support to add labels to actionset in kanctl create actionset command

[viveksinghggits]

Change Overview

Fixes: #2433

This PR adds capability in kanctl so that we can specify the labels for the actionset that is going to get created. To do this, it introduces a flag called --labels to kanctl create actionset command.

kanctl create actionset --help
Create a new ActionSet or override a <parent> ActionSet

Usage:
  kanctl create actionset [flags]

Flags:
  -a, --action string                action for the action set (required if creating a new action set)
...
...
  -k, --kind string                  resource kind to apply selector on. Used along with the selector specified using --selector/-l (default "all")
      --labels string                Labels that should be added to the created actionset. Multiple labels can be separate by comma(,) (eg: --labels key=value,foo=bar)
...
...

Pull request type

Please check the type of change your PR introduces:

• 🚧 Work in Progress
• 🌈 Refactoring (no functional changes, no api changes)
• 🐹 Trivial/Minor
• 🐛 Bugfix
• 🌻 Feature
• 🗺️ Documentation
• 🤖 Test

Issues

• fixes Support to create actionset with specific labels using kanctl #2433

Test Plan

kanister/pkg/kanctl (label-actionset*) » go test
OK: 4 passed
PASS
ok  	github.com/kanisterio/kanister/pkg/kanctl	0.030s

• 💪 Manual
• ⚡ Unit test
• 💚 E2E

kanctl create actionset --action backup --namespace kanister --blueprint mysql-blueprint --statefulset mysql/mysql-release --profile mysql/s3-profile-qgbmj --labels=key=value --dry-run 
apiVersion: cr.kanister.io/v1alpha1
kind: ActionSet
metadata:
  creationTimestamp: null
  generateName: backup-
  labels:
    key: value
spec:

kanctl create actionset --action backup --namespace kanister --blueprint mysql-blueprint --statefulset mysql/mysql-release --profile mysql/s3-profile-qgbmj --labels=key=value,keytwo=valuetwo --dry-run
apiVersion: cr.kanister.io/v1alpha1
kind: ActionSet
metadata:
  creationTimestamp: null
  generateName: backup-
  labels:
    key: value
    keytwo: valuetwo
spec:

kanctl create actionset --action backup --namespace kanister --blueprint mysql-blueprint --statefulset mysql/mysql-release --profile mysql/s3-profile-qgbmj --labels=key=value,keytwo=valuetwo, --dry-run
Error: invalid labels value. make sure the value for field --labels is correct
Usage:
  kanctl create actionset [flags]

[e-sumin]

Overall, except the raised question, LGTM to me.