Hyundai CAN-FD: Universal gear checks

[sunnyhaibin]

Description

The refactor's goal is to improve the gear checking logic to be applicable to both HDA2 and non-HDA2 Hyundai vehicles, which was previously only applied to non-HDA2 cars.

Verification

This is tested in the following active PRs:

• HKG: Car Port for Genesis G80 2024 (2.5T, HDA2) #32633
• HKG: Car Port for Genesis GV70 2022 (3.5T, HDA2) #31704

[github-actions]

Thanks for contributing to openpilot! In order for us to review your PR as quickly as possible, check the following:

• Convert your PR to a draft unless it's ready to review
• Read the contributing docs
• Before marking as "ready for review", ensure:
  • the goal is clearly stated in the description
  • all the tests are passing
  • the change is something we merge
  • include a route or your device' dongle ID if relevant

[sshane]

Both of these cars are peculiarly missing the ADAS ECU but have bus structures similar to HDA2 vehicles. Until we understand what's going on, I don't want to merge a change like this where we don't fully understand why it's needed.