clean up registry

[wonderflow]

Make sure all these following Definitions can really work.

1. add knative as workload and add componentDefinition for it.
2. fix knative auto scale trait, make it real work

apiVersion: core.oam.dev/v1beta1
kind: TraitDefinition
metadata:
  annotations:
    definition.oam.dev/description: "Auto scale for knative serving"
  name: knative-autoscale
  namespace: vela-system
spec:
  appliesToWorkloads:
    - knative-serving # this should be some knative like workload
  schematic:
    cue:
      template: |-
        import "encoding/json"
        patch: {
          metadata: annotations: {
              "my.autoscale.ann": json.Marshal({
                  "minReplicas": parameter.min
                  "maxReplicas": parameter.max
              })
          }
        }
        parameter: {
          min: *1 | int
          max: *3 | int
        }

3. fix expose trait and add into kubevela chart as inner trait

apiVersion: core.oam.dev/v1beta1
kind: TraitDefinition
metadata:
  name: expose
  namespace: vela-system
spec:
  schematic:
    cue:
      template: |-
        parameter: [string]: int

        outputs: {
          for k, v in parameter {
              "\(k)": {
                  apiVersion: "v1"
                  kind:       "Service"
                  spec: {
                      selector:
                          app: context.name
                      ports: [{
                          port:       v
                          targetPort: v
                      }]
                  }
              }
          }
        }

4. Delete the code of PodDisruptionBudgetTrait and write a CUE based trait instead, put it into registry. https://kubernetes.io/docs/tasks/run-application/configure-pdb/

[chivalryq]

add expose trait done see:kubevela/kubevela#1678