feat(patch): allow package creation via patch.

[Zenithar]

Context

Patch was initially designed to apply modification on existing packages. I recently added the ability to remove a package via patch (initial purpose of filter) so symmetrically I add the ability to create packages.

This feature will only work with the strict path matcher to use the given path as package name.

Sample

apiVersion: harp.elastic.co/v1
kind: BundlePatch
meta:
  name: "package-creator"
  owner: security@elastic.co
  description: "Create a targeted package"
spec:
  rules:
    - selector:
        matchPath:
          strict: "application/created-package"
      package:
        # Flag to be created if not exists
        create: true

        # On package annotation
        annotations:
            # Update annotation value with new secret
            update:
                secret-service.elstc.co/encryptionKey: |-
                    UcbPlrEJ9jZEQX06n8oMln_mCl3EU2zl2ZVc-obb7Dw=

        # On package data
        data:
            # Update annotations
            annotations:
                # Update annotation value with new secret
                update:
                    secret-service.elstc.co/encryptionKey: |-
                        DrZ-0yEA18iS7A4xaR_pd-relh9KMtTw2q11nBEJykg=
            kv:
                add:
                    "key": "value"