Add GPS message types, consolidate SBG messages, create common messag…

[NoahSprenger]

This pull request includes significant changes to the src/command.rs, src/lib.rs, and src/sensor.rs files, as well as an update to the Cargo.toml file. The changes primarily focus on restructuring the message and sensor data handling, adding new message types, and removing redundant code.

Restructuring message and sensor data handling:

• src/lib.rs: Introduced RadioMessage and CanMessage structs to differentiate between radio and CAN messages, and added RadioData and CanData enums to encapsulate different types of data. [1] [2]

Adding new message types:

• src/sensor.rs: Added a comprehensive list of new GPS message types under the Gps enum, leveraging the ublox crate for various GPS data references.
• src/sensor.rs: Simplified and combined existing sensor data structures, such as merging EkfNav1 and EkfNav2 into EkfNav, and Imu1 and Imu2 into Imu. [1] [2] [3]

Removing redundant code:

• src/command.rs: Removed the CommandData struct and its new method, simplifying the Command enum. [1] [2]
• src/sensor.rs: Removed the Sensor struct and its new method, along with other unused sensor data structures.

Dependency updates:

• Cargo.toml: Added the ublox crate with serde feature for handling GPS data.

These changes streamline the codebase, improve message handling, and enhance the flexibility for future expansions.