Use DisplayScreenName when sending an evil notification

[jgknight]

Summary

According to OSCAR docs we should be sending the formatted screen name in the evil notification snac. Also we were incorrectly sending the warning level of recipient instead of the sender in the sender's TLVUserInfo block.

Testing Done

Before Fix
Sending a warning would result in the unformatted screen name appearing in the warning dialog. Also bots like smartersmarterchild would be unable to find the chat context for warnings received during conversations with formatted screen names.

After Fix
The formatted name appears in the warning dialog. Also smartersmarterchild can now correctly keep track of the incoming warning to the chat context it was received with.

The updated unit test passes, and the rest of the repo unit tests also pass.

=== RUN   TestICBMService_EvilRequest/transmit_anonymous_warning_from_sender_to_recipient
    /Users/josh/code/retro-aim-server/foodgroup/mock_buddy_broadcaster_test.go:211: PASS:       BroadcastBuddyArrived(string,mock.argumentMatcher)
    /Users/josh/code/retro-aim-server/foodgroup/mock_message_relayer_test.go:154: PASS: RetrieveByScreenName(state.IdentScreenName)
    /Users/josh/code/retro-aim-server/foodgroup/mock_message_relayer_test.go:154: PASS: RelayToScreenName(string,state.IdentScreenName,wire.SNACMessage)
    /Users/josh/code/retro-aim-server/foodgroup/mock_feedbag_manager_test.go:417: PASS: BlockedState(state.IdentScreenName,state.IdentScreenName)
--- PASS: TestICBMService_EvilRequest/transmit_anonymous_warning_from_sender_to_recipient (0.00s)