A hierarchy of types

[nstarman]

Fine grain protocols of attrs and methods.

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[nstarman]

@ntessore, I had to change the name of the Hubble and critical density aggregate protocols and I am not thrilled with the new name. Perhaps we should systematize the naming structure a little better:

1. has an attribute / method -> Has<X>
2. low-level aggregator, e.g. HasOmegaTot0 & HasOmegaTot -> [Prefix I haven't thought of]TotalDensity[Suffix]
   • the suffix for components would be Component
   • Distance for the distances, like Tcmb ?
   • Nothing for the extras, like Hubble and scale factor?
3. mid-level aggregator, e.g. DistanceMeasures -> [Whatever makes sense]
4. high-level aggregator: Cosmology : e.g. Cosmology and StandardCosmology

What would be nice is to have a consistent name with HasHubbleMethods and HasCriticalDensityMethods and HasBackgroundT, which I've put in as placeholder names.
We can keep the Component suffix for the components, but maybe we should add Density to Has<X>Component?
I'm not sure what a good prefix for the low-level aggregator is. Has isn't bad, but it's not great either because then something like the Methods suffix feels necessary, which I don't particularly like.

[codecov-commenter]

Codecov Report

Merging #48 (98b218a) into main (424d54b) will increase coverage by 4.40%.
The diff coverage is 100.00%.

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@@            Coverage Diff             @@
##             main      #48      +/-   ##
==========================================
+ Coverage   77.16%   81.56%   +4.40%     
==========================================
  Files          13       13              
  Lines         289      358      +69     
==========================================
+ Hits          223      292      +69     
  Misses         66       66              

Impacted Files	Coverage Δ
src/cosmology/api/__init__.py	100.00% <100.00%> (ø)
src/cosmology/api/_array_api/__init__.py	100.00% <100.00%> (ø)
src/cosmology/api/_components.py	91.26% <100.00%> (+6.51%)	⬆️
src/cosmology/api/_core.py	78.94% <100.00%> (-1.06%)	⬇️
src/cosmology/api/_distances.py	77.77% <100.00%> (+7.18%)	⬆️
src/cosmology/api/_extras.py	92.68% <100.00%> (+4.68%)	⬆️
src/cosmology/api/_standard.py	93.33% <100.00%> (ø)
src/cosmology/api/compat/_core.py	100.00% <100.00%> (ø)
src/cosmology/api/compat/_standard.py	100.00% <100.00%> (ø)

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[ntessore]

This is a great improvement! Needs a couple of fixes, nothing major.

[nstarman]

I named it TemperatureCMB so that it had the same order as T_CMB.

[ntessore]

One small question whether HoverH0 was intentional or typo, but LGTM!