Switch from enum_primitive to num-enum?

[waywardmonkeys]

enum_primitive hasn't been maintained in years and is an old style macro.

We could migrate to enum_derive_primitive or num-enum.

It seems like num-enum is more actively maintained and is part of the larger ecosystem.

Before doing this, we'll want some PRs to land (including one that isn't submitted yet) to avoid merge conflicts.

[mrghosti3]

What purpose does any of those crates perform? To me it just simpler to implement From trait for the enums that need to be converted from numbers.

On other note, enum_derive_primitive looks better, as it is simpler and with lesser dependencies.