Email address validation too strict - no international characters allowed

[heslegend]

Describe the bug
The email address validation does not allow special international characters like e.g. the german ä, ö, ü.

Steps to reproduce:

1. Try to submit feedback
2. Enter an email address containing the special character

Wiredash SDK Info
Which SDK are you using?
1.9.0

On which platform are you seeing the crash?
Android, but should be the same on iOS.

Flutter SDK
not relevant

Screenshots

[passsy]

You're right! We need to relax the email validation in the SDK and the backend

Dankeschön!