Build: configure+cts_scheduler: allow skipping hash-table-broken tests

Overall design neglected variance brought into the game when hash
tables are used + glib 2.59.0 (providing their implementation)
introduced exactly such a variance. By default, those tests won't
be skipped, but with --disable-hash-affected-tests=try, it will
be figured out automatically per the configure-time detected version
of glib library.

References:
https://bugs.clusterlabs.org/show_bug.cgi?id=5378
https://lists.clusterlabs.org/pipermail/users/2019-January/016115.html