sfrmaker

fix(MODFLOW 6 SFR package data): by default write zeros for each grid dimension for inactive reaches instead of 'none'; retain option to write 'none' for backwards compatibility with older versions of MODFLOW 6.

fix(Lines): support any CRS unit strings that contain meter/metre/m, feet/foot/ft. Previously, for example strings like 'US survey foot' were not being recognized.

fix(test_flows.py): convert specified line_id(s) to strings and explicitly sort the new_lines to try to fix flaky test_add_to_perioddata2 test