[SDK-3145] Add Auth0Client parameter to logout and add view to telemetry.env for iOS

[adamjmcgrath]

Changes

For iOS:

• Add a view property to the telemetry's env which tells us which View Controller the user is doing Web Auth with (ASWebAuthenticationSession, SFAuthenticationSession or SFSafariViewController)

For all platforms:

• Add the auth0Client telemetry parameter to the logout URL for clearSession

Testing

• Added unit tests for updating the telemetry and logging in
• Manually tested logout because I couldn't figure out how to unit test it

Checklist

• I have read the Auth0 general contribution guidelines
• All existing and new tests complete without errors
• All active GitHub checks have passed

[Widcket]

Thanks for taking care of this while I was away! Just left a couple of comments about using a0_decodeBase64URLSafe() to decode the telemetry info.