feature: expand benchmarking, try ASV

[wpbonelli]

Is your feature request related to a problem? Please describe.

FloPy currently has a very small set of hand-rolled benchmarks, including

• init/load/write time for a small test model:

  flopy/autotest/test_modflow.py

  Line 1352 in 3e176d0

  def test_model_load_time(function_tmpdir, benchmark):

• MP7 pathline/endpoint data load time:

  flopy/autotest/test_modpathfile.py

  Line 264 in 3e176d0

  def test_get_destination_pathline_data(

It might be worthwhile to a) benchmark a broader set of models/utils, and b) minimize ad hoc code needed to achieve this.

Describe the solution you'd like

Maybe benchmark load/write for all test models provided by a models API as proposed in #1872, as well as any widely used pre/post-processing utils. Could also try ASV — it has been adopted by other projects like numpy, shapely, and pywatershed.

Describe alternatives you've considered

We could just stick with pytest-benchmark and a bit of scripting instead of moving to ASV.

Additional context

This would help quantify performance improvements from the ongoing effort to use pandas for file IO