See https://github.com/junegunn/fzf/discussions/3792
This allows us to separately capture the standard error from fzf and its
child processes, and there's less chance of user errors of redirecting
the error stream and hiding fzf.
- Update to latest tcell which has 24 bit Windows support
- light renderer under Windows defaults to Dark256, if possible
- Respect TCELL_TRUECOLOR
- Remove tcell 1.3 references