C++ refactoring: ak.argsort

[ioanaif]

No description provided.

[codecov]

Codecov Report

Merging #1304 (929920e) into main (8e68200) will increase coverage by 1.71%.
The diff coverage is 77.65%.

Impacted Files	Coverage Δ
src/awkward/_v2/_connect/numba/arrayview.py	96.24% <ø> (ø)
src/awkward/_v2/_connect/numba/layout.py	87.01% <ø> (ø)
src/awkward/_v2/_prettyprint.py	63.79% <0.00%> (ø)
src/awkward/_v2/_slicing.py	84.43% <ø> (ø)
src/awkward/_v2/contents/__init__.py	100.00% <ø> (ø)
src/awkward/_v2/forms/__init__.py	100.00% <ø> (ø)
src/awkward/_v2/identifier.py	55.69% <ø> (ø)
.../awkward/_v2/operations/convert/ak_from_buffers.py	85.71% <ø> (ø)
src/awkward/_v2/operations/convert/ak_from_cupy.py	25.00% <0.00%> (-50.00%)	⬇️
src/awkward/_v2/operations/convert/ak_from_iter.py	92.30% <ø> (ø)
... and 165 more

[jpivarski]

This all looks great! It looks like you're done, too, so I'll merge it.

Thanks!