add reason enum to use instead of string value for error messages #277

Job	Run time
Rustfmt (ubuntu-latest, x86_64-unknown-linux-gnu)	3s
Test Individual Features NoStd (binary)	12s
Test Individual Features (binary)	9s
Test Individual Features NoStd (json)	13s
Build (ubuntu-latest, x86_64-unknown-linux-gnu)	6s
Test Individual Features (json)	14s
Test (ubuntu-latest, x86_64-unknown-linux-gnu)	14s
Test Individual Features NoStd (ron)	16s
Build (ubuntu-latest, x86_64-pc-windows-gnu)	1m 40s
Test Individual Features (ron)	23s
Test Individual Features NoStd (toml)	14s
Build (ubuntu-latest, wasm32-unknown-unknown)	11s
Test Individual Features (toml)	7s
Build (macos-latest, x86_64-apple-darwin)	21s
Test No Std (ubuntu-latest, x86_64-unknown-linux-gnu)	22s
Build (windows-latest, x86_64-pc-windows-msvc)	1m 24s
	6m 9s

Provide feedback