Choose the smallest colocation id among all matches (#4559)
Choose the smallest colocation id among all matches (#4559)

Currently we choose an arbitrary colocation id from all the matches for
a colocation id. This could mean that 2 distributed tables, which have
the same scheme could go into different colocation groups. This fix
makes sure that the same match will go to the same colocation group.
citusdata/citus,citusdata/citus,citusdata/citus,citusdata/citus,citusdata/citus