This commit implements a basic IP prefix dictionary
that allows storing IPv4/IPv6 prefixes and
matching them against a single IP address on query
time. This allows for doing IP -> ASN matching and
other similar things on query time.

The implementation is basic for start, using a
simple bitwise trie and reusing interface for
complex key dictionaries (so using tuple instead
of UInt32/FixedString(16) as the key). A faster
bitwise trie implementation (like poptrie) is
desired to improve lookup performance and
memory consumption with large prefix tables.

By default start with 2^4 elements

this fixes build on Debian

StorageBuffer: explicitly disable support for PREWHERE, because possibility of wrong query results [#CLICKHOUSE-2999].

* allow separate table key / hash key, and use
  std::string / StringRef for generic variant as
  it has built-in storage and StringRef is supported
  by the hash table, this avoids infinitely
  growing arena with serialised keys
* use power-of-2 size for alpha vector for faster
  binning without using modulo
* use custom grower and allocator for SpaceSaving
  to start with smaller tables
* store computed hash in counter for faster
  reinsertion of smallest element

* fixes missing setHash on reinsert
* reuses hash when emplacing value

Improved performance of inserting into StorageDistributed with very high number of shards (not tested) [#CLICKHOUSE-2].