Allow configurable v4/v6 address matching behavior for SAI indexes on CQL inet columns

The inet type in CQL allows ipv4 and ipv6 address formats to mix in the same column, and while there is a standard conversion between v4 and v6, equivalent addresses are not considered equal by Cassandra, when it comes to their usage in keys or in filtering queries. However, in SAI queries, equivalent v4 and v6 addresses ARE considered equal. Even if this behavior is useful, it might be a good idea to make the default behavior consistent with filtering, and allow the index configuration to control whether or not to consider them equal. (We have precedent for this w/ case-insensitive indexing of text columns, etc.)