Fix: ScamBlocker does not scan edited messages

[KonstantineVashalomidze]

Fixes: #1516

ScamBlocker only checked messages on creation (onMessageReceived), not on edit (onMessageUpdated). A user could send a clean message then edit it to contain scam content.

Extracted the detection logic into a private handleMessage(Message, Guild) method and called it from both event handlers. Several private methods were updated to accept Message and Guild parameters directly instead of the event object.

Tested this manually (Since there is no ScamBlockerTest) on a local test discord server.

[CLAassistant]

All committers have signed the CLA.

[Zabuzard]

This was done on purpose as we never ever had scam that came through an edit so far.
Is this now a real use case? If not, I would probably vote to reject this PR as it would only bear risks (more false positives) than covering more (real) scam.

[KonstantineVashalomidze]

@Zabuzard
Thanks for the feedback. I see your point. If such cases hasn't happened or doesn't happen usually I will be happy to close this PR.

[KonstantineVashalomidze]

Closing this pull request as it might introduce false positives of scam detection during edit, and since no scammers are trying to edit their messages with scam content that much.