Support Multi-Arch Images for Control-Planes & Node Pools

DoD:

We need to ensure we have parity with OCP and support heterogeneous clusters

https://github.com/openshift/enhancements/pull/1014

• Define UX for multi arch HostedCluster/NodePool input. E.g always enforce multi arch image, this might not be possible because of impact for image registry on disconnected clusters https://github.com/openshift/enhancements/pull/1014#discussion_r798444099. 
• Pinned images e.g CAPI, autoscaler, mapprover need to support multiarch.

Goal

• Provide a way to install with varied architecture NodePools with the ability to autoscale
• Support provisioning heterogeneous architecture management cluster in Hypershift.
• Define UX for multi arch HostedCluster/NodePool input. E.g always enforce multi arch image, this might not be possible because of impact for image registry on disconnected clusters https://github.com/openshift/enhancements/pull/1014#discussion_r798444099. 

Why is this important?

• Necessary to enable workloads with different architectures in the same Hosted Clusters.
• Cost savings brought by more cost effective ARM instances

Scenarios

1. I have an x86 hosted cluster and I want to have at least one NodePool running ARM workloads
2. I have an ARM hosted cluster and I want to have at least one NodePool running x86 workloads

Acceptance Criteria

• Dev - Has a valid enhancement if necessary
• CI - MUST be running successfully with tests automated
• QE - covered in Polarion test plan and tests implemented
• Release Technical Enablement - Must have TE slides

Dependencies (internal and external)

1. The management cluster must use a multi architecture payload image.
2. The target architecture is in the OCP payload
3. MCE has builds for the architecture  used by the worker nodes of the management cluster

Done Checklist

• CI - CI is running, tests are automated and merged.
• Release Technical Enablement <link to Feature Enablement Presentation>
• DEV - Upstream documentation merged: <link to meaningful PR or GitHub Issue>
• DEV - Enhancement merged: <link to meaningful PR or GitHub Issue>
• QE - Test plans in Polarion: <link or reference to Polarion>
• QE - Automated tests merged: <link or reference to automated tests>
• DOC - Downstream documentation merged: <link to meaningful PR>