Non-EVM support with backwards compatibility

[connorwstein]

Here we just commit to family specific selector ymls for backwards compatibility. Meaning

• EVM: selectors.yml, test_selectors.yml all Go code using those are renamed to have evm in the filename and non-public methods similarly prefixed with evm.
• Solana: selectors_solana.yml follows the same pattern where the yaml key is the family specific ID and the selector + name is a value.
• selectors.go is reserved for family agnostic Go code. We can extend it to use all the family specific yamls for various family agnostic functions (like looking up the name for a selector)

[connorwstein]

closing in favour of #70