When editing figures, pressing Tab cancels the edit

[kingjon3377]

When editing a figure (especially a "named figure"), the user will likely want to use the Tab key to navigate between the fields and buttons in the edit panel. However, this key is intercepted by the table and treated as an instruction to leave editing mode.

(When fixing this, it'd also be nice to make "enter" switch to editing mode when not editing, and "enter" in one of the text boxes apply pending edits.)