E-mail change should emit `userUpdated` instead of `signedIn`

[spydon]

Describe the bug

Currently we (and the JS SDK) are emitting the wrong state for when a user updates their e-mail.

This should be fixed in V3, since it's technically a breaking change.

Library affected

supabase_flutter

Reproduction

No response

Steps to reproduce

No response

System Info

All

Platform

Linux

Logs

No response

Validations

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• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Supabase Flutter/Dart Library issue and not an issue with the Supabase platform. If it's a Supabase platform related bug, it should likely be reported to supabase/supabase instead.
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• The provided reproduction is a minimal reproducible example of the bug.