Test cases:
  fd --color always | fzf --ansi --delimiter /
  fd --color always | fzf --ansi --delimiter / --nth -1 --color fg:dim,nth:regular
  fd --color always | fzf --ansi --delimiter / --nth -1 --color fg:dim:strip,nth:regular
  fd --color always | fzf --ansi --delimiter / --nth -1 --color fg:dim:strip,nth:regular --raw
  fd --color always | fzf --ansi --delimiter / --nth -1 --color fg:dim:strip,nth:regular,hidden:strikethrough --raw
  fd --color always | fzf --ansi --delimiter / --nth -1 --color fg:dim:strip,nth:regular,hidden:strip:strikethrough --raw
  fd --color always | fzf --ansi --delimiter / --nth -1 --color fg:dim:strip,nth:regular,hidden:strip:dim:strikethrough --raw

Close #4432

Example:
  # foo was not displayed in italic
  echo -e "\x1b[33;3mfoo \x1b[mbar" | fzf --ansi --color fg:dim,nth:regular --nth 1

Example:
  echo -e "\x1b[33;3mfoo \x1b[34;4mbar\x1b[m baz" | fzf --ansi --no-color

Test cases:

1. 'jump' should show alternating background colors even when 'alt-bg' is
not defined as before.

  go run main.go --bind load:jump

Two differences:
  * The alternating lines will not be in bold (was a bug)
  * The marker column will not be rendered with alternating background color

2. Use alternating background color when 'alt-bg' is set

  go run main.go --color bg:238,alt-bg:237
  go run main.go --color bg:238,alt-bg:237 --highlight-line

3. 'selected-bg' should take precedence

  go run main.go --color bg:238,alt-bg:237,selected-bg:232 \
                 --highlight-line --multi --bind 'load:select+up+select+up'

4. Should work with text with ANSI colors

  declare -f | perl -0777 -pe 's/^}\n/}\0/gm' |
    bat --plain --language bash --color always |
    go run main.go --read0 --ansi --reverse --multi \
                   --color bg:237,alt-bg:238,current-bg:236 --highlight-line

---

Close #4354
Fix #4372

* 'pathname' is a new tiebreak option for prioritizing matches occurring
  in the file name of the path.

* `--scheme=path` will automatically set `--tiebreak=pathname,length`.

* fzf will automatically choose `path` scheme when the input is a TTY device,
  where fzf would start its built-in walker or run `$FZF_DEFAULT_COMMAND`
  which is usually a command for listing files.

Close #4191

If you do not want 'current-fg' to inherit attributes of 'fg', prefix it
with 'regular:' to reset them.

  # italic and underline
  fzf --color fg:italic,current-fg:underline

  # only underline
  fzf --color fg:italic,current-fg:regular:underline