Full Resolution Wheel Encoder

[SM-dot]

A discussed in #58, this utilizes a more accurate approach to calculate distance and velocity. In case of under sampling, indicates an error to transition in the Faulted State for the FSM.

Changes

• Upgrade to RPPAL v0.18.0 for using InputPin with Raspberry Pi 5
• Create enums for EncoderState and EncoderDiff with numeric traits derived from num_enum
• Encode two pins of wheel encoder as 2-bit gray code to track full 16-count resolution
• Calculate velocity on all increments rather than on interval
• Handle undersampling by returning an Err

[taesungh]

Rather than having a separate copy, we'll want to modify the existing implementation in wheel_encoder.rs

[taesungh]

Some notes about implementation, I've already looked into addressing most of them. Noticed in testing we'll also need to update the version of RPPAL.

[ryescholin]

Tested in lab -- works! tysm

[samderanova]

Approving since wheel encoder works as stated above and to unblock integration testing with other peripherals. We'll want to use meters instead of feet but we can do this in another issue.