fix and improve multiport handling

fix and improve multiport handling

The multiport `--ports` parameter is an `OR` match on source
and destination ports, so we should not use it.

We also don't actually use the port count, so let the port
range parser simply return a boolean and use the counter
only for the internal check. This also fixes a regression
caused by the previous multiport check which caused a single
port range to be recognized as a multiport option while it
did not have to be one, causing entries such as the SMB
macro to be added with `--match multiport` mistakenly, which
refused to accept the source port option.

Additionally, we now allow the case with 1 multiport and 1
single port entry: In order for the iptables command to
accept this the single port entry must come first, otherwise
it'll be passed to the multiport matcher (because why
shouldn't it interpret a singular `--Xport` as an alias to
the plural version `--Xports`... *sigh*).

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Fixes: 6a241ca745f7 ("check multiport limit in port ranges")