* handle ip adresses in term aggregation
Stores IpAdresses during the segment term aggregation via u64 representation
and convert to u128(IpV6Adress) via downcast when converting to intermediate results.
Enable Downcasting on `ColumnValues`
Expose u64 variant for u128 encoded data via `open_u64_lenient` method.
Remove lifetime in VecColumn, to avoid 'static lifetime requirement coming
from downcast trait.
* rename method
`ColumnValues` wrongly located in column_values/column.rs due to
historical reason moves to column_values/mod.rs
u128 stuff gets its own directory like u64 stuff.