Script Generator: Improved Keyboard Shortcuts

# Feature Description
As an instrument scientist, I would like to be able to add text by simply typing in the text boxes, and add rows with keyboard shortcts so that I can more quickly use the script generator.

## Explanation

Requested by EMU instrument scientist. Add any obvious keyboard shortcuts to the script generator, such as ctrl-n for a new line, cut/copy/paste. Additionally make cells editable after a single click.

### Additional Information
Not applicable

# Acceptance Criteria
- Commonly used keyboard shortcuts such as ctrl-n/c/x/v are implemented in the script generator
- A single click on a cell allows a user to type in that cell

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