Numpad and new layout

[AaronVerDow]

I've been working on some number pads for the kbdpad but was running into trouble doing more advanced combinations of labels instead of a single, global font & size.

This pull request adds:

• A new way to define layouts
• A default numpad layout
• An iRacing replay layout

This may also be useful for: https://github.com/rsheldiii/KeyV2/issues/89

I was hoping to get some feedback on the new layout specifically to see if there was some way we could make it behave more like the other layouts while still allowing each key to be individually tweaked.