Notes zoom buttons don't work

The + and - buttons on the "Notes" section of the speaker window do not have any effect on the size of the Notes text (and don't appear to do anything else, either).

Start by locating the speaker window's Notes section and the handlers for its + and - buttons. Reproduce the issue, then trace whether the controls are connected to the Notes text styling. Done means both buttons visibly change the size of the Notes text and no longer have an otherwise empty effect.

Written by the indexing model from the issue text.