Support Google Identity Provider

[Supereg]

Problem

We recently added support for Sign in with Apple. We want to extend this support for Single-Sign-On Providers to other Providers like Google.

Solution

Leverage the existing infrastructure, the FirebaseIdentityProviderAccountService, to add support for other identity providers like a Google-based one.

Additional context

This would require some minor adjustments to the FirebaseAccount target. As Google requires an additional SDK, we would implement that support as a separate target. The existing infrastructure would need some minor adaption to allow to source the IdentityProvider-specific operations externally.

Code of Conduct

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