Update the GCP docs to their own page #4617
Description
What content needs to be created or modified?
We need a page like the "Authenticating to Azure/AWS" pages but for GCP. We need to take what was started here by @antontroshin and bring it out into its own page to simplify the GCP component docs. Today, all the components in Dapr except for the Firestore component support implicit credentials.
Describe the solution you'd like
Where should the new material be placed?
https://docs.dapr.io/developing-applications/integrations/
under a new page called "GCP"
The associated pull request from dapr/dapr, dapr/components-contrib, or other Dapr code repos
Additional context