More MAIL QoL tweaks

1. Notify player of New Mail when it is received by ANY character on any game account linked to the same email address. (Example: I have 2 accounts linked to the same email address. I'm playing Character#3 on the first account. Character#2 on the 2nd account receives mail. I am notified in-game that my other character received mail.)  This will make it much easier for people to get in touch with each other when people have multiple chars.

2. Add Mail notifications to F9 Chat log. It's easy to miss it when it's just onscreen for a second and then gone. Especially helpful to be able to review the name of the sender. This follows #1 above, meaning the chat log message would include the name of the char that received the mail.

3. Within the Mailbox display, add column for # of Attached items.