Fix disabled text and number property inputs by removing keypress preventDefault() calls interfering from unrelated panes.

[tripp528]

Description

Commented out some preventDefault calls on keypress events that were being called from panes that weren't the target for the event.

Motivation and Context

Text and number property inputs were not functioning when a separate embeddings, text, or image pane was present and had a keypress callback handler registered to it.

Fixes #935

[tripp528]

I'm not sure what those preventDefault() calls were meant for exactly, but this doesn't seem to have introduced any issues thus far. A cleaner fix might be to check if e.g. the ImagePane was the target before calling preventDefault.