Implement total_sz/ boson number symmetries in ED

Created by: gcarleo

Current ED operations discard the constraints on the total number of particles / total_sz imposed in Hilbert, this should be improved and implemented in the number_to_state and state_to_number operations of the corresponding hilbert objects

see also #328 (closed)

added enhancement label

Created by: gcarleo

Anybody interested in working on this? @kchoo1118 @alexwie

mentioned in merge request !357 (merged)

added v3.0 label

Created by: gcarleo

Implemented in 3.0

closed