Their names are not perfect, so let's keep them as internal functions,
until we figure out how/if we want to expose this.
This reverts 0445126c2 (Undunder __fish_is_nth_token, 2021-06-29) (but I
did it without "git revert").
Closes#8008
We keep __fish_is_nth_token for compatibility and edit the
implementations of __fish_is_nth_token, __fish_is_first_token and
__fish_is_token_n to use fish_is_nth_token
"function --argument" is not a thing, it's "--argument-names". This only
accidentally works because our getopt is awful and allows abbreviated
long options.
Similarly, one argparse test used "--d" instead of "-d" or "--def".
I hate doing this but I am tired of touching a fish script as part of
some change and having `make style` radically change it. Which makes
editing fish scripts more painful than it needs to be. It is time to do
a wholesale reformatting of these scripts to conform to the documented
style as implemented by the `fish_indent` program.
