Feature: Allow keyboard keys to click IN, OUT, DROP buttons

[nojronatron]

While using the form, I found it difficult to use the Tab key or mouse to move the cursor/caret to the necessary field or UI component, especially when bulk-entering lots of data (i.e. 30 or more).

Leverage key clicks to complete each bib entry to speed-up the process and spare the keyboard's TAB key.

IN => i
OUT => o
DROP => d

Once i, o, or d is clicked, the form should behave exactly as it does when the IN, OUT, or DROP buttons are clicked (or the space bar is pressed while selected).