feat: Multi StackConfigPolicy per cluster

[tehbooom]

This PR allows for a cluster to have multiple StackConfigPolicies (SCPs). Avoids conflicts of the same resources based on the weights of the policy with the lowest weight having the highest priority. If two policies have the same weight and the same resources it will fail and the phase will be changed to CONFLICT.

Here is a simple table showing what should pass and what should fail

Weight	Resource	Result
Same	Different	✅
Same	Same	❌
Different	Same	✅
Different	Different	✅

The following was tested and passed interchangeably.

---
# different weights same policy should pass with policy-1 winning
apiVersion: stackconfigpolicy.k8s.elastic.co/v1alpha1
kind: StackConfigPolicy
metadata:
  name: cluster-policy-1
spec:
  weight: -1
  elasticsearch:
    snapshotRepositories:
      policy-1-backups:
        type: s3
        settings:
          bucket: "policy-1-backups"
          region: "us-west-2"
---
apiVersion: stackconfigpolicy.k8s.elastic.co/v1alpha1
kind: StackConfigPolicy
metadata:
  name: cluster-policy-2
spec:
  weight: 11
  elasticsearch:
    snapshotRepositories:
      policy-1-backups:
        type: s3
        settings:
          bucket: "policy-2-backups"
          region: "us-east-1"
---
## Different weights different policies should pass
apiVersion: stackconfigpolicy.k8s.elastic.co/v1alpha1
kind: StackConfigPolicy
metadata:
  name: cluster-policy-1
spec:
  weight: 10
  elasticsearch:
    snapshotRepositories:
      policy-1-backups:
        type: s3
        settings:
          bucket: "policy-1-backups"
          region: "us-west-2"
---
apiVersion: stackconfigpolicy.k8s.elastic.co/v1alpha1
kind: StackConfigPolicy
metadata:
  name: cluster-policy-2
spec:
  weight: 11
  elasticsearch:
    snapshotRepositories:
      policy-2-backups:
        type: s3
        settings:
          bucket: "policy-2-backups"
          region: "us-east-1"
---
## Same weight different repositories should pass
apiVersion: stackconfigpolicy.k8s.elastic.co/v1alpha1
kind: StackConfigPolicy
metadata:
  name: cluster-policy-1
spec:
  weight: 10
  elasticsearch:
    snapshotRepositories:
      policy-1-backups:
        type: s3
        settings:
          bucket: "policy-1-backups"
          region: "us-west-2"
---
apiVersion: stackconfigpolicy.k8s.elastic.co/v1alpha1
kind: StackConfigPolicy
metadata:
  name: cluster-policy-2
spec:
  weight: 10
  elasticsearch:
    snapshotRepositories:
      policy-2-backups:
        type: s3
        settings:
          bucket: "policy-3-backups"
          region: "us-east-1"
---
# Policy 2 wins with telemetry.optIn set to true
apiVersion: stackconfigpolicy.k8s.elastic.co/v1alpha1
kind: StackConfigPolicy
metadata:
  name: kibana-policy-1
spec:
  weight: 1
  kibana:
    config:
      telemetry.optIn: false
---
apiVersion: stackconfigpolicy.k8s.elastic.co/v1alpha1
kind: StackConfigPolicy
metadata:
  name: kibana-policy-2
spec:
  weight: 0
  kibana:
    config:
      telemetry.optIn: true

The following will fail

---
# Same weight same policy must fail
apiVersion: stackconfigpolicy.k8s.elastic.co/v1alpha1
kind: StackConfigPolicy
metadata:
  name: cluster-policy-1
spec:
  weight: 10
  elasticsearch:
    snapshotRepositories:
      policy-1-backups:
        type: s3
        settings:
          bucket: "policy-1-backups"
          region: "us-west-2"
---
apiVersion: stackconfigpolicy.k8s.elastic.co/v1alpha1
kind: StackConfigPolicy
metadata:
  name: cluster-policy-2
spec:
  weight: 10
  elasticsearch:
    snapshotRepositories:
      policy-1-backups:
        type: s3
        settings:
          bucket: "policy-2-backups"
          region: "us-east-1"

This was also tested with a ECK 3.1.0 then upgraded. Previous SCPs will have a default value of 0.

[prodsecmachine]

🎉 Snyk checks have passed. No issues have been found so far.

✅ security/snyk check is complete. No issues have been found. (View Details)

✅ license/snyk check is complete. No issues have been found. (View Details)

[github-actions]

🔍 Preview links for changed docs

• docs/reference/api-reference/main.md