Macro structform::impl_numeric_input_with_stringops

macro_rules! impl_numeric_input_with_stringops {
    ($numeric_input: ident, $type_name: literal, $type: ty, $underlying_numeric_type: ty) => { ... };
    ($numeric_input: ident, $type_name: literal, $type: ty, $underlying_numeric_type: ty, $min: expr, $max: expr) => { ... };
}

Implements ParseAndFormat<$type> for $numeric_input<$type>, and also implements ParseAndFormat<Option<$type>>> for $numeric_input<Option<$type>>.

This will parse by first converting the string input to an $underlying_numeric_type, which should be something like u32 or i64, then calling std::convert::TryFrom<$underlying_numeric_type>. If the input string is empty after trimming, then parse will return a ParseError::Required for the ParseAndFormat<$type> case, and return None for the ParseAndFormat<Option<$type>> case.

Formatting is done using std::string::ToString.