In strum 0.23 the EnumString derive now implements TryFrom<&str> as well in #186

Problem with this is that TryFrom<&str> is automatically derived for &str: Into<MyEnum>: https://doc.rust-lang.org/stable/std/convert/trait.TryFrom.html#impl-TryFrom%3CU%3E-for-T

This means that after strum 0.22 it is no longer possible to implement From<&str> for MyEnum and/or Into<MyEnum> for &str. We would want to implement those especially if we have a #[strum(default)] field which would make parsing infallible (?).

Besides reverting, another fix would be to automatically implement From/Into if parsing is infallible

Same as #228 I imagine