lint & format io/iohandlers{a-d}.py

[jGaboardi]

xref #589

This PR

• breaks out lint & format – io/iohandlers/* #630 (part 1 of $n$)
• formats and lints io/iohandlers{a-d}.py

[codecov]

Codecov Report

Merging #637 (3d39f42) into main (b7e6a85) will decrease coverage by 0.0%.
The diff coverage is 90.3%.

@@           Coverage Diff           @@
##            main    #637     +/-   ##
=======================================
- Coverage   83.9%   83.9%   -0.0%     
=======================================
  Files        139     139             
  Lines      14972   14970      -2     
=======================================
- Hits       12564   12562      -2     
  Misses      2408    2408             

Files	Coverage Δ
libpysal/io/iohandlers/arcgis_dbf.py	87.7% <100.0%> (ø)
libpysal/io/iohandlers/arcgis_swm.py	96.4% <100.0%> (-<0.1%)	⬇️
libpysal/io/iohandlers/csvWrapper.py	96.8% <100.0%> (-0.1%)	⬇️
libpysal/io/iohandlers/dat.py	95.0% <100.0%> (ø)
libpysal/io/iohandlers/db.py	88.0% <100.0%> (ø)
libpysal/io/iohandlers/arcgis_txt.py	72.1% <57.1%> (ø)