feat: Add select.nodepool parameter type

[rushtehrani]

What this PR does:

Which issue(s) this PR fixes:

Fixes onepanelio/core#

Special notes for your reviewer:

Checklist

Please check if applies

• I have added/updated relevant unit tests
• I have added/updated relevant documentation

Required

• I accept to release these changes under the Apache 2.0 License

[rushtehrani]

@Vafilor issues so far:

• Comments in Workflows (might be the case with Workspaces too) are getting removed - for example I commented out nodeSelector and it was gone when I went back to edit the template.
• Adding a select.nodepool and saving seems to auto inject options when I go back to edit the template.
• This maybe due to the UI changes but filters are not working - they're all returning 403 errors, looks like labels is being passed as a namespace"

time="2020-12-28T06:00:32Z" level=warning msg="finished unary call with code PermissionDenied" error="rpc error: code = PermissionDenied desc = Permission denied. Namespace: 'labels', Verb: 'get', Group: '', Resource '', Name: ''" grpc.code=PermissionDenied grpc.method=GetLabels grpc.service=api.LabelService grpc.start_time="2020-12-28T06:00:32Z" grpc.time_ms=3.078 span.kind=server system=g

Note that migrations don't have this issue - this only happens when saving from web UI.