feat(auth): add signInWithOAuth

[grdsdev]

What kind of change does this PR introduce?

Close #257

How OAuth worked before?

Before the OAuth implementation consisted of 3 steps:

1. Call the getOAuthSignInURL method that returned a URL type.
2. Use the URL returned in step 1 to initiate the OAuth flow, this was up to the developer to implement, on completion of this step, it should have a result URL that contains the token/code.
3. Use the result URL from step 2 to call session(from:) method that would parse the URL and import the session into the client.

How it works after this PR?

Everything from How OAuth worked before? is still valid in case user wants full control of the flow.

But now there are 2 convenience methods (built on top of the already existent methods).

Sign in leveraging the steps mentioned above but injecting the Step 2

let session = try await signInWithProvider(provider: .google) { url in
    let resultURL = await customFlowImplementation(url: url) // Use url for initiating the flow, some options could be implementing a web view, using `openURL` method from `UIApplication`, and manually observing for deep links.
    return resultURL // Containing #token=abc.def.ghi
}

Sign in using ASWebAuthenticationSession on the platforms that supports it (Recommended)

let session = try await signInWithProvider(provider: .google) { session in 
    // additional configuration to session object
    session.presentationContextProvider = YourCustomImplementation()
}

Other changes introduced

• Instead of providing a redirectURL on all methods, you can pass one when initializing the client, and it will be used as the default if none is provided in the method.

[dshukertjr]

Just to double-check, the following code on the PR body is actually meant to be signInWithOAuth, correct?

let session = try await signInWithProvider(provider: .google) { session in
// additional configuration to session object
session.presentationContextProvider = YourCustomImplementation()
}

[grdsdev]

Yes @dshukertjr thanks for that.