Create uom error message filter similar to tnfilt

[iliekturtles]

tnfilt _{(at least the slightly patched version I submitted in a PR (it looks like rustc has changed the amount of qualification in shows in the error messages, since tnfilt was written) which has been ignored thus far)} does work with uom, but it doesn't help much. For example, it turns this

Quantity<(dyn Dimension<L = PInt<UInt<UTerm, B1>>, J = Z0, Kind = (dyn Kind + 'static), N = Z0, T = NInt<UInt<UInt<UTerm, B1>, B0>>, M = Z0, Th = Z0, I = Z0> + 'static), (dyn uom::si::Units<f32, luminous_intensity = uom::si::luminous_intensity::candela, mass = uom::si::mass::kilogram, length = uom::si::length::meter, time = uom::si::time::second, thermodynamic_temperature = uom::si::thermodynamic_temperature::kelvin, amount_of_substance = uom::si::amount_of_substance::mole, electric_current = uom::si::electric_current::ampere> + 'static), f32>

into this

Quantity<(dyn Dimension<L = PInt<U1>,              J = Z0, Kind = (dyn Kind + 'static), N = Z0, T = NInt<U2>,                        M = Z0, Th = Z0, I = Z0> + 'static), (dyn uom::si::Units<f32, luminous_intensity = uom::si::luminous_intensity::candela, mass = uom::si::mass::kilogram, length = uom::si::length::meter, time = uom::si::time::second, thermodynamic_temperature = uom::si::thermodynamic_temperature::kelvin, amount_of_substance = uom::si::amount_of_substance::mole, electric_current = uom::si::electric_current::ampere> + 'static), f32>

(alignment mine) which is almost nothing on the scale of the total amount of noise.

All it does is things like

• PInt<UInt<UTerm, B1>> -> PInt<U1>
• NInt<UInt<UInt<UTerm, B1>, B0>> -> NInt<U2>

If all that noise can be reduced to something like this Quantity<m^1 s^-2, Kind, f32>, then it would be really useful. I'll have a go, and see how close I can get to that ideal, but progress will be very slow, for lack of time.

Originally posted by @jacg in #293 (comment)