Log Message:
csvlens: update to 0.12.0.

Freeze first n columns when scrolling via f<n> (#62, #117)
Support searching in header row (#102)
Support moving find mode cursor horizontally via n / N
Support library usage without clap dependency (#118 by @jqnatividad)
Fix search highlighting when columns are filtered
Fix column scrolling for CSV with irregular last row (#99)