* column size calculating routines now take into account multiple streams [#CLICKHOUSE-2831]
* rename for clarity
* use more appropriate method for calculating table size
* add info about total uncompressed part size to system.parts and system.parts_columns [#CLICKHOUSE-2831]
* rename columns for clarity [#CLICKHOUSE-2831]
* count shared substreams only once [#CLICKHOUSE-2831]