add annotation for workspacetemplate crd

Created by: RolandMa1986

Signed-off-by: Roland.Ma rolandma@yunify.com

What type of PR is this? /kind bug

What this PR does / why we need it: RawExtention Type in WorkspaceTemplate type was missing when upgrading CustomResourceDefinition from apiextensions.k8s.io/v1beta1 to apiextensions.k8s.io/v1.

type: object
properties:
  foo:
    x-kubernetes-preserve-unknown-fields: true

Which issue(s) this PR fixes:

Related kubesphere#3794 (closed)

/cc @zryfish @wansir