As title, this pr adds --strict flag to first and last command, so they will raise error on empty list. This is a follow up to #17054

Release notes summary - What our users need to know

By default, first and last will return null on empty list, this pr is going to add --strict to make it returns on error.

> [] | first --strict
Error: nu::shell::access_beyond_end

  × Row number too large (empty content).
   ╭─[entry #1:1:6]
 1 │ [] | first --strict
   ·      ──┬──
   ·        ╰── index too large (empty content)
   ╰────

Tasks after submitting

NaN