Empties a projection's table and replays every stored event into it, in order.
mix vic.projection.rebuild MyApp.Projections.ListSummary
mix vic.projection.rebuild MyApp.Projections.ListSummary MyApp.Projections.OtherUse it after fixing an on clause, or after adding a projection for events that already
happened. The events must still be in domain_events. Readers see the table fill up again
while it runs, so run it in a quiet period; if it fails part-way the projection is partial
and the task says so and exits non-zero: fix the cause and run it again.
Each projection is rebuilt on its own: a failure in one does not stop the others.