feat(transform): Add hash string conversion

[MisterMX]

Description of your changes

This adds three new string conversion function to patch transforms, ToSha1, ToSha256, ToSha512, that generate a hash from the JSON representation of the input value.

I have:

• Read and followed Crossplane's contribution process.
• Run make reviewable to ensure this PR is ready for review.
• Added backport release-x.y labels to auto-backport this PR if necessary.

How has this code been tested

composition.yaml

---
apiVersion: apiextensions.crossplane.io/v1
kind: Composition
metadata:
  name: test-string-tojson
spec:
  compositeTypeRef:
    apiVersion: example.org/v1alpha1
    kind: XSecret
  resources:
    - name: secret
      base:
        apiVersion: secretsmanager.aws.crossplane.io/v1beta1
        kind: Secret
        metadata:
          name: # patched
          annotations:
            hash: # patched
        spec:
          forProvider:
            region: eu-central-1
            stringSecretRef:
              name: # patched
              namespace: # patched
              key: # patched
          providerConfigRef:
            name: example
      patches:
        # Policy
        - fromFieldPath: "spec.parameters"
          toFieldPath: "metadata.annotations[hash]"
          transforms:
            - type: string
              string:
                type: Convert
                convert: ToSha1
        # SecretRef
        - fromFieldPath: "spec.parameters.secretRef.name"
          toFieldPath: "spec.forProvider.stringSecretRef.name"
        - fromFieldPath: "spec.parameters.secretRef.key"
          toFieldPath: "spec.forProvider.stringSecretRef.key"
        - fromFieldPath: "metadata.labels[crossplane.io/claim-namespace]"
          toFieldPath: "spec.forProvider.stringSecretRef.namespace"

xrd.yaml

---
apiVersion: apiextensions.crossplane.io/v1
kind: CompositeResourceDefinition
metadata:
  name: xsecrets.example.org
spec:
  group: example.org
  claimNames:
    kind: Secret
    plural: secrets
  names:
    kind: XSecret
    plural: xsecrets
  versions:
    - name: v1alpha1
      served: true
      referenceable: true
      schema:
        openAPIV3Schema:
          type: object
          properties:
            spec:
              type: object
              properties:
                parameters:
                  type: object
                  properties:
                    secretRef:
                      type: object
                      description: The Kubernetes Secret whose data will be sent as string to AWS.
                        The secret needs to exist in the same namespace as this claim.
                      properties:
                        key:
                          type: string
                          description: Optional key whose value should be uploaded. If not set, the
                            whole map in the Secret data will be used.
                        name:
                          type: string
                          description: Name of the Kubernetes Secret resource in the same namespace
                            as this claim.
                      required:
                        - name
              required:
                - parameters

xrc.yaml

---
apiVersion: v1
kind: Secret
metadata:
  name: example-secret
  namespace: default
type: Opaque
stringData:
  password: passw0rd
---
apiVersion: example.org/v1alpha1
kind: Secret
metadata:
  name: example-secret
  namespace: default
spec:
  parameters:
    secretRef:
      name: example-secret

[turkenh]

Is this the first usage of generics in Crossplane 🤔

[MisterMX]

Its a feature of the newer Go version. Is that a problem? Its only a very small function.

[turkenh]

Thanks @MisterMX!

Looks like we need a rebase here too.