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
We now have a builtin that can do URL escaping so use it. I can't find
any uses of our private `__fish_urlencode` function in any Oh-My-Fish or
Fisherman code so remove it.
In the C/POSIX locale EOF on the tty wasn't handled correctly due to a change
a few months ago to fix an unrelated problem with that locale. What is
surprising is that the core fish code doesn't explicitly depend on
input_common_readch returning WEOF if a character isn't seen within
`wait_on_escape_ms` after an escape.
Fixes#3214
