Use modern solution for tri-layer in sofle default layout

[rafal0p]

Description

As per docs handling it in process_record_user is no longer necessary.

I don't own OLED version, so I'd like to ask the dear reviewer to verify if print_status_narrow still works properly after that change.

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]

Just a heads up, either version is valid, and have their own quirks. Like the layer state function won't let you activate the third layer (the "adjust" layer here) without the first two layers (raise and lower, here) being active. That may not be desirable behavior, in some cases/configs.

[zvecr]

This wont work as KC_LOWER and friends are now a non implemented keycodes.

They need to be removed from the custom keycodes enum, and replaced with,

#define KC_LOWER MO(_LOWER)

[rafal0p]

@drashna, I knew about this limitation, but aforementioned feature (activating _ADJUST directly) is not not present in the default layout. But maybe you're right, and for educational purposes it's actually better to leave it as-is?

@zvecr, thanks for spotting the issue, pushed the change with MO(_LOWER) (instead of #define), do you happen to know if they are equivalent?

[zvecr]

Equivalent as long as you do not need to do MO(_ADJUST)