Refactor 'NumKeypad' module to match tab name 'Record'

[tjsr]

For consistency with other pages, I have refactored the NumKeypad.py module to 'Record.py', and split out the relevant code so that only the Keypad related code now exists in its own module.

I'd like to have this implemented so that I can start doing more major work to these components including:

• Adding better hints for the user what is going on if they try to use these controls but it appears nothing occurs (such as when they have no race file open, or other situations I've encountered where it doesn't accept or process the crossing).
• Splitting out the keypad tabs more granularly so that code can be better worked on and tested in isolation.
• Start utilising better logging from Add Log util class #162
• Clean up inconsistent button and font usage

[tjsr]

I would also suggest that all of the page tab classes be renamed to *Page.

This gives them a consistent name and makes it clear their intended usage within the application as a UI view, rather than either an individual control or controller class/module.