HCP CLI should expose "pausedUntil" flag

Value Statement

The HostedCluster and NodePool specs already has "pausedUntil" field.

 pausedUntil: description: 'PausedUntil is a field that can be used to pause reconciliation on a resource. Either a date can be provided in RFC3339 format or a boolean. If a date is provided: reconciliation is paused on the resource until that date. If the boolean true is provided: reconciliation is paused on the resource until the field is removed.' type: string  

This option is currently not exposed in "hypershift create cluster" command. 

In order to support HCP create/update automation template with ClusterCurator, users should be able to "hypershift create cluster" with the PausedUntil flag.

Definition of Done for Engineering Story Owner (Checklist)

• I can create a hosted cluster with "hypershift create cluster <platform> --pausedUntil true"
• HostedCluster and NodePool CRs from this command should contain "pausedUntil" field in the spec.
• The hosted cluster creation should be paused until the pausedUntil=true field is removed from the HostedCluster and NodePool CRs 
• This should work for agent, kubevirt and aws platforms.

Development Complete

• The code is complete.
• Functionality is working.
• Any required downstream Docker file changes are made.

Tests Automated

• [ ] Unit/function tests have been automated and incorporated into the
  build.
• [ ] 100% automated unit/function test coverage for new or changed APIs.

Secure Design

• [ ] Security has been assessed and incorporated into your threat model.

Multidisciplinary Teams Readiness

• [ ] Create an informative documentation issue using the [Customer
  Portal_doc_issue template](
  https://github.com/stolostron/backlog/issues/new?assignees=&labels=squad%3Adoc&template=doc_issue.md&title=),
  and ensure doc acceptance criteria is met. Link the development issue to
  the doc issue.
• [ ] Provide input to the QE team, and ensure QE acceptance criteria
  (established between story owner and QE focal) are met.

Support Readiness

• [ ] The must-gather script has been updated.