Pipeline should check the integrity of the metadata.json generated during a run.

[bpblanken]

If we claim to load a family:

• Does the family exist in the project table with the right samples?
• Does the family table exist?
• Is the family included in the lookup table?

[bpblanken]

Also... is it even possible to check the family tables performantly?

[lynnpais]

Revisit with the new backend