Bug 29705: In test suite merge IssuingRules with CirculationRules

Bug 29705: In test suite merge IssuingRules with CirculationRules

After Bug 18936, in test suite, there is still t/db_dependent/Koha/IssuingRules.t and t/db_dependent/Koha/IssuingRules/
This patch moves IssuingRules.t inside CirculationRules.t and renames dir t/db_dependent/Koha/IssuingRules.
And adds DB transation in each first-level subtest.

Also renames in :
  use constant GUESSED_ITEMTYPES_KEY => 'Koha_IssuingRules_last_guess';

Test plan :
Run prove t/db_dependent/Koha/CirculationRules.t
prove t/db_dependent/Koha/CirculationRules/*
prove t/db_dependent/Circulation/maxsuspensiondays.t

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>