tools/net/ynl: accept IP string inputs

The ynl tool uses display-hint to know when to format IP addresses in
printed output, but not to parse IP addresses from --json input. Add
support for parsing ipv4 and ipv6 strings.

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250211120127.84858-5-donald.hunter@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>