[Inbox] Relocate the "message sent" notification

[barrybrown]

Problem statement:

In the Canvas Inbox, the "message sent" popup notification covers the buttons for a few seconds. After sending a message, the next thing I want to do is archive the message, but the notification obscures the button I want to click.

Proposed solution:

Move the notification up or down about 1/2 inch, so that it doesn't cover up anything the user would want to click on. The banner could be made smaller, too, since there's a lot of unused whitespace in it.

User role(s):

instructor,student,ta