[RFE] Add support for listing Google projects

[mantis-toboggan-md]

Is your feature request related to a problem? Please describe. When creating or importing a GKE cluster through the UI, users need to manually enter the ID of the gcp project they want to use for the given cluster, even if they have valid google cloud credentials available. This is rather tiresome poor UX.

Describe the solution you'd like The norman api currently supports a few endpoints for listing other gcp resources used in GKE cluster management. The UI would like this expanded to include listing projects (https://cloud.google.com/resource-manager/reference/rest/v1/projects/list), so we can offer users a dropdown of available project IDs instead of requiring them to type in an ID each time they create/import clusters. https://github.com/rancher/rancher/blob/3ae1c6ac8d3524f8ded4544f1db75fc9e07911a5/pkg/api/norman/customization/gke/listers.go

Additional context

[Jono-SUSE-Rancher]

@MKlimuszka and @prachidamle - I assigned this over to you guys for Frameworks. I think it could maybe be Highlander, but it looks more like it would come from the API instead of from GKE itself. If I am wrong, feel free to re-assign to Highlander.