#9 select_a_space() method in TSAdapter

[Kia Teymourian]

The distribution Manager sends an Entry to the TSAdapter and ask which subspace is the best candidate to be migrated to a remote kernel and

- TSAdapter write the spaceURI of the Candidate Subspace in an Entry back

or

- it writes null back when there is no subspace to be migrated.

This depends on another feature request

See [ 2609194 ] select_a_space()

[Kia Teymourian]

The TSadpater can inform the DM to migrate a subspace inside the notification Entry.
We could add a field space to the OverloadDMEntry, We migrate from the lowest level subspace up, choosing the smallest spaces first.

The TSadapter need only to name one of the subspaces in the lowest level.