MINOR: stktable/cli: support v6tov4 and v4tov6 conversions

MINOR: stktable/cli: support v6tov4 and v4tov6 conversions

Add a special treatment for the IPV4 and IPV6 cases in
table_process_entry_per_key() function so that input string is parsed
in best effort (STR to pseudo type ADDR): input format is first considered
over table type and then let smp_to_stkey() do the type conversion for us
when needed.

This patch heavily depends on:
- "MEDIUM: stktable/cli: simplify entry key handling"

And optionally depends on:
- 72514a44 ("MEDIUM: tools/ip: v4tov6() and v6tov4() rework")