Update lint checks

[gboeing]

This PR adds a few new CI lint checks, and fixes the codebase to conform accordingly. It also improves exception handling throughout and introduces a couple new custom error types.

[codecov]

Codecov Report

Merging #1041 (80cdb62) into main (710755f) will increase coverage by 0.12%.
The diff coverage is 90.76%.

@@            Coverage Diff             @@
##             main    #1041      +/-   ##
==========================================
+ Coverage   97.59%   97.72%   +0.12%     
==========================================
  Files          24       24              
  Lines        2454     2461       +7     
==========================================
+ Hits         2395     2405      +10     
+ Misses         59       56       -3     

Impacted Files	Coverage Δ
osmnx/settings.py	100.00% <ø> (ø)
osmnx/speed.py	87.87% <ø> (ø)
osmnx/geocoder.py	89.74% <33.33%> (+0.13%)	⬆️
osmnx/features.py	96.37% <91.66%> (-0.12%)	⬇️
osmnx/_downloader.py	97.42% <95.65%> (-0.34%)	⬇️
osmnx/_version.py	100.00% <100.00%> (ø)
osmnx/elevation.py	100.00% <100.00%> (ø)
osmnx/folium.py	100.00% <100.00%> (ø)
osmnx/graph.py	99.35% <100.00%> (-0.01%)	⬇️
osmnx/io.py	100.00% <100.00%> (+3.38%)	⬆️
... and 2 more

... and 2 files with indirect coverage changes