Add a JSON spec check on build

[harrison-e]

Changes

• CAN types (Message, NetField, Point) can no longer be deserialized with unspecified members (ones not listed in the spec or in libs/calypso-cangen/can_types.rs). For example, if a field foo: 1 were added somewhere in one of the JSON files, and it was not listed in can_types.rs, Calypso would fail to build.
• build.rs now contains a CAN spec validation check, which scans Embedded-Base/cangen/can-messages/* to validate that the spec is obeyed properly. The following checks are performed:
  • Message descriptions only contain letters, whitespaces, and underscores
  • Message totals are byte-aligned
  • Fields that use a Sim enum have the frequencies for the enum add to 1
  • Points that are sent are at most 32 bits
  • Signed points are 8, 16, or 32 bits
  • Little endian points are 8, 16, or 32 bits
  • Points that are less than a byte should not specify endianness (no-op check)
  • IEEE754 32-bit float points are of size 32 bits
  • File IO works properly (Rust can access the can-messages directory and all its entries properly)
• Code for performing the JSON validation is in libs/calypso-cangen/src/validate.rs
  • CANSpecError enum, used for descriptive error messages, uses thiserror crate to make the enum
  • Functions to validate all CAN spec, an individual CAN spec file, and an individual CAN Message
• Fixed a bug that would ignore default field in encodable CAN Messages.

Notes

• Moved CANGEN_SPEC_PATH to calypso-cangen (from daedalus)

To Do

• GitHub action check to Embedded-Base/cangen
• Possible error tracing with anyhow crate? (likely unnecessary, not sure how much value traces would provide)

Closes #81

[jr1221]

One wierd thing with submodules. Other than that absolutely loving it. Works hella fast too at least on my computer. thiserror seems cool never used it before.

[jr1221]

me when a stale review dismissal doesnt allow me to merge a one line change: 😿