Clean up TCU

[BZhu792]

Compiles but DO NOT MERGE UNTIL VALIDATED

Pull Request (PR) into Code-2022

Code Description

Modified TCU to delete unused functions and variables. Better code commenting and cleanup.

Testing Description

Compiles, but MUST TEST on vehicle before merge. Not doing so can lead to severe consequences.

Additional Information

Put any additional datasheets, information, and/or useful links here.

Checklist

• Is this code linked to a new board or board rev?
• • Is there a PR for that board in circuits-2022? If so, please pause until that PR is merged.
• If you made a change or addition or deletion to the CAN library, did you inform the Data Aq lead?
• Did you test the code in real-world conditions before submitting?
• • Did you use CPU Speed = 720 MHz (overclock) and Optimize = Fastest when testing with Teensy 4.x?
• • Did you use CPU Speed = 144 MHz (overclock) and Optimize = Fastest with LTO when testing with Teensy 3.5?
• • Did you use CPU Speed = 120 MHz (overclock) and Optimize = Fastest with LTO when testing with Teensy 3.2?
• • Did you use Teensyduino 1.56 with Arduino 1.8.19 when testing with the latest libraries from main?
• Did you pull main into your branch?
• • Did you check for merge conflicts?
• • Did you resolve any that occurred? If you are having trouble or are confused, contact a lead!
• Did you fill out the above template?
• Did you assign the right people for review (on the right)?