Make use of the `$Phishing` flag to detect phishing emails

[hamza221]

Is your feature request related to a problem? Please describe.

Delivery agents can mark a message as phishing with $Phishing flag. https://datatracker.ietf.org/doc/html/rfc9051#name-flags-message-attribute

Describe the solution you'd like

Make use of the $Phishing flag to reinforce the mail app's Phishing detection.

• Add a new check in PhishingDetectionService
• Display message eg ' Message is highly likely to be a phishing email '
• Follow the rfc ( placing the message in the \Junk special-use mailbox ...)

Describe alternatives you've considered

No response

Additional context

No response