Bug 12787: Reorganise t/db_dependent files

Bug 12787: Reorganise t/db_dependent files

This patch tries to reorganise test files in the db_dependent directory:
- Circulation_Branch.t       has been moved to Circulation/Branch.t
- Circulation_issuingrules.t has been moved to Circulation/CalcDateDue.t
- Circulation_Issuingrule.t  has been moved to Circulation/GetHardDueDate.t
- Circulation_dateexpiry.t   has been moved to Circulation/dateexpiry.t
- Circulation_issue.t        has been moved to Circulation/issue.t
- Circulation_transfers.t    has been moved to Circulation/transfers.t
- Items_DelItem.t            has been moved to Items/DelItem.t
- BiblioObject.t             has been moved to Koha/Biblio.t
- Members_Attributes.t       has been moved to Members/Attributes.t
- Members_columns.t          has been moved to Members/columns.t
- Circulation_OfflineOperation.t   has been moved to Circulation/OfflineOperation.t
- Koha_template_plugin_KohaDates.t has been moved to Template/Plugin/KohaDates.t
- Koha_template_plugin_Branches.t  has been moved to Template/Plugin/Branches.t
- Reports/Guided.t, ReportsGuided.t and Reports_Guided.t have been
  merged

Test plan:
Confirm that all the modified tests still pass

Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Brendan Gallagher <bredan@bywatersolutions.com>