Refactor interpolation structure

[RuneDominik]

After discussion in the context of #221 with @maxnoe, he asked to change the current interpolation structure in a way that has completely decoupled inter- and extrapolator classes that are instantiated by a specific estimator class for each IRF HDU. This structure also handles the data checks currently done in the interpolator classes. This removes the old interpolate_xyz functions (definitively a breaking change) in favor of an API with actual reusable objects and some kind of configurability.

Please check carefully, if this structure is now as desired. I'll add missing documentation afterwards.

[codecov]

Codecov Report

Patch coverage: 97.57% and project coverage change: +0.12 🎉

Comparison is base (c939be6) 92.46% compared to head (489e954) 92.59%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #228      +/-   ##
==========================================
+ Coverage   92.46%   92.59%   +0.12%     
==========================================
  Files          49       50       +1     
  Lines        2005     2120     +115     
==========================================
+ Hits         1854     1963     +109     
- Misses        151      157       +6     

Impacted Files	Coverage Δ
.../interpolation/tests/test_griddata_interpolator.py	100.00% <ø> (ø)
pyirf/interpolation/quantile_interpolator.py	98.14% <85.71%> (-1.86%)	⬇️
...ion/tests/test_component_estimator_base_classes.py	96.03% <96.03%> (ø)
pyirf/interpolation/component_estimators.py	98.33% <98.33%> (ø)
pyirf/interpolation/__init__.py	100.00% <100.00%> (ø)
pyirf/interpolation/base_interpolators.py	96.29% <100.00%> (-2.24%)	⬇️
pyirf/interpolation/griddata_interpolator.py	100.00% <100.00%> (ø)
...irf/interpolation/tests/test_base_interpolators.py	100.00% <100.00%> (+1.70%)	⬆️
...tests/test_component_estimator_specific_classes.py	100.00% <100.00%> (ø)
.../interpolation/tests/test_quantile_interpolator.py	100.00% <100.00%> (ø)

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