Add lighting menu for kbd67mkiirgb v3

[SEApodEErman]

Description

Adds the missing menus block to v3/kbdfans/kbd67mkii/kbd67mkiirgbv3.json for lighting menu support.

Current V3 definitions had no menus for lighting since the last time an issue was made for it (#1131) was when VIA's lighting UI did not support per-key RGB/RGB Matrix at that time and was understandably closed.

The reason I went with a custom menu instead of "menus": ["qmk_rgb_matrix"] was due to the QMK source firmware only compiling 26 of the RGB Matrix animations. The uncompiled effects shift every later mode down and the built-in menu assumes the full effect order (at least in my testing). This would cause the dropdown to mislabel entries and address nonexistent modes on this board and Custom UI specification seems to support this.

Do note that I only specify kbd67mkiirgb v3 since it's the only PCB I own, I'm unsure how other versions would react to the changes.

QMK Pull Request

qmk/qmk_firmware#13714

VIA Keymap Pull Request

qmk/qmk_firmware#8085
(PR was made for v1/v2 but in the current userspace repository, this seems to apply to all kbd67mkiirgb versions.)

Checklist

• The VIA support for this keyboard is MERGED in QMK master already (MANDATORY)
• VIA keymap is MERGED in VIA userspace master already (MANDATORY)
• The VIA definition follows the guide here: https://caniusevia.com/docs/layouts
• I have a V3 JSON version for this keyboard definition.(MANDATORY)
• I have used explicit QMK lighting keycode modules instead of the legacy qmk_lighting module.
• I have formatted the JSON file to have consistent formatting with the rest of the repository.
• I have tested this keyboard definition using VIA's "Design" tab.
• I have tested this keyboard definition with firmware on a device.
• I have assigned alpha keys and modifier keys with the correct colors.
• The Vendor ID is not 0xFEED