TopicLinkClick: convert 'ip' (bigint) -> 'ip_address' (inet)

When accessed over IPv6, the ip address of the user is a 128-bit number,
too big for PostgreSQL's bigint data type. Since PostgresSQL has the
built-in inet type, which handles both IPv4 and IPv6 addresses, we
should use that instead. Where this is done elsewhere in the codebase,
the column is called ip_address, so we should follow that convention as
well.
views: convert 'ip' (bigint) -> 'ip_address' (inet)

This fixes all known issues when connecting to discourse over IPv6.

This table has no primary key, so the migration is done with update_all,
for each ip address in the views table. Since this table can potentially
grow quite large, this process might take a long time. I don't know any
way around this, though.