MINOR: cfgparse: always suggest the section names on an unknown keyword

MINOR: cfgparse: always suggest the section names on an unknown keyword

When an unknown keyword is met in a section, cfg_find_best_match() looks
for the closest match among the keywords registered for that section,
plus an optional list of extra words passed by the caller, which
cfg_parse_global() and cfg_parse_listen() were using to pass a list of
a few known hard-coded section names. But this resulted several times
in some names not being matched (e.g. "resolvers" which was later added
but only for "global"), or others still not being known, e.g.

  $ printf 'global\n\tcrt-stor\n' | ./haproxy -c -f /dev/stdin
  [ALERT] : parsing [/dev/stdin:2] : unknown keyword 'crt-stor' in
    'global' section; did you mean 'crt-store' maybe ?

Let's have the function always consider all known section names since
they are always permitted, that is much more effective and will no
longer require to hard-code certain combinations. This completely drops
the extra argument that's no longer used.