Since we will now replicate reference tables each time we add node, we need to ensure
that test space is clean in terms of reference tables before any add node operation.
For this purpose we had to change order of multi_drop_extension test which caused
change of some of the colocation ids.
Added a new UDF, mark_tables_colocated(), to colocate tables with the same
configuration (shard count, shard replication count and distribution column type).
create_reference_table() creates a hash distributed table with shard count
equals to 1 and replication factor equals to shard_replication_factor
configuration value.
With this change, master_copy_shard_placement and master_move_shard_placement functions
start to copy/move given shard along with its co-located shards.
Burak Yucesoy
Eren Basak
Metin Doslu