[Keyboard] Add splitkb.com's Halcyon Lily58 rev2

[VeyPatch]

Halcyon Lily58 rev2

Description

This pull request adds support for splitkb.com's latest product, the Halcyon Lily58 rev2. It is the latest keyboard in our new Halcyon range.

This PR is mostly similar to our Halcyon Kyria rev4 PR which has previously been merged. Hopefully this way we won't have anything major blocking this PR. For more information about naming and peripheral configuration, see the Halcyon Kyria rev4 PR as well.

The Halcyon Lily58 rev2 is available for sale at splitkb.com

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).