`repr()` is misbehaving

[yunruse]

I think I've leant on rich too much, because without it, the following is a bit borked:

>>> from noether import meter
>>> meter
Unit(value=1, stddev=None, dim=length  # length, length, distance, height, width, breadth, depth)
>>> conf.display_repr_code
False

This should only happen when display_repr_code is True. Additionally, the comment should not display when it is True!

This should be enforced by some unit testing, I think.

[yunruse]

repr(Dimension) and str(Dimension) seem swapped. repr should show alternate names and str not IMO

[yunruse]

Additionally,

• __repr_code__ should just be repr_code,
• str(meter) should just return "meter"

[yunruse]

we should also expect no * in str():

>> str(K * m)
'1 K m'

[yunruse]

Fixed for v1.0.