feat: add string trimming and padding functions#248

Merged

jacques-n merged 7 commits intosubstrait-io:mainfrom richtia:string_trimming_padding

Jul 28, 2022

+158-3

Commits on Jul 25, 2022

Commits on Jul 26, 2022

Commits on Jul 27, 2022

refactor: update descriptions for lpad and rpad
richtia
committed

Commits on Jul 28, 2022

refactor: remove center function
richtia
committed