Should be able to specify a name when deriving ArrowField

[teh-cmc]

You should be able to do this:

#[derive(ArrowField)]
#[arrow_field(name = "rerun.tuid")]
pub struct Tuid {
    /// Approximate nanoseconds since epoch.
    time_ns: u64,

    /// Initialized to something random on each thread,
    /// then incremented for each new [`Tuid`] being allocated.
    inc: u64,
}

in order to yield this:

impl arrow2_convert::field::ArrowField for Tuid {
    type Type = Self;

    fn data_type() -> arrow2::datatypes::DataType {
        let datatype = arrow2::datatypes::DataType::Struct(<[_]>::into_vec(Box::new([
            <u64 as arrow2_convert::field::ArrowField>::field("time_ns"),
            <u64 as arrow2_convert::field::ArrowField>::field("inc"),
        ])));
        DataType::Extension("rerun.tuid".into(), Box::new(datatype), None)
    }
}

Similarly, the Component trait should always generate extension types, automatically injecting the component name into the ArrowField definition (related to #1696).

This is not just about dev experience, this opens many doors in terms of data inspection.

[teh-cmc]

Closing: we're moving away from arrow2-convert.