Load stubs from TOML instead of JSON files (#277)

* Remove unused stub files

* Convert the stub files to TOML, eliminate the `serde_json` dependency

Author: jessebraham

Cargo.lock

@@ -57,7 +57,6 @@ regex = "1.6.0"
 rppal = { version = "0.13.1", optional = true }
 serde = { version = "1.0.145", features = ["derive"] }
 serde-hex = "0.1.0"
-serde_json = "1.0.86"
 serialport = "4.2.0"
 sha2 = "0.10.6"
 slip-codec = "0.3.3"