[Keymap] Improve andrebrait keymap

[andrebrait]

Description

Remove the dependency on lib8tion. I was using sin8 in order to get either a 1 or a 0, which can be accomplished with just some bitwise operations, so I just changed it. This makes things a lot simpler. I also renamed some defines inside the keymap file to make it slightly easier to parse when reading.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[drashna]

Thanks!