refactor(flopy_io, notebooks): update path cleaning mechanism

[wpbonelli]

#1711 cleaned up absolute paths containing usernames from notebooks and introduced a function relpath_printstr to trap relpath errors due to different drives on Windows. This isn't always sufficient to keep absolute paths out of notebooks if used with a path sharing no prefix with the starting path (e.g. if an exe isn't in the flopy project dir, but somewhere like /usr/bin)

• Rename relpath_printstr -> relpath_safe since it returns the edited path without printing. Update usages. Refactor to follow builtin relpath signature and defaults.

• Introduce a function scrub_login to obfuscate login names with ***. Optionally scrub in relpath_safe.

• Suppress output in notebooks with silent=True and collect with report=True before printing, avoiding the executable log statement if possible, otherwise use scrub_login() to hide username in absolute paths

• Lint notebooks and test scripts

[codecov]

Codecov Report

Merging #1728 (72f6930) into develop (58d92fa) will decrease coverage by 0.1%.
The diff coverage is 86.6%.

@@            Coverage Diff            @@
##           develop   #1728     +/-   ##
=========================================
- Coverage     71.9%   71.9%   -0.1%     
=========================================
  Files          253     253             
  Lines        55987   55996      +9     
=========================================
+ Hits         40270   40275      +5     
- Misses       15717   15721      +4     

Impacted Files	Coverage Δ
flopy/mbase.py	69.1% <ø> (ø)
flopy/export/shapefile_utils.py	90.2% <75.0%> (-0.4%)	⬇️
flopy/utils/flopy_io.py	79.0% <88.2%> (-0.3%)	⬇️
flopy/export/utils.py	65.2% <100.0%> (ø)
flopy/utils/check.py	75.7% <100.0%> (ø)