Bug 23059: reserve_stats.pl: Simplify reservestatus

Bug 23059: reserve_stats.pl: Simplify reservestatus

This patch does the following:
[1] Go back to four statuses: Cancelled, Filled, Waiting or Placed.
    Placed is used as collective name for all other statuses: pending
    (placed), processing (found==P) or transit (found==T). Placed before
    anyway.
[2] Allow translation of these statuses in the template. Remove the sub
    reservestatushuman.
[3] The output of changeifreservestatus is considerably shorter and less
    ugly in the constructed sql statement.

Test plan:
[1] Use reservestatus as row, as column and only as filter (clicking few
    statuses).
[2] Verify that the shown statistics meet your expectations.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Emily Lamancusa <emily.lamancusa@montgomerycountymd.gov>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>