Bug 15783: AddAuthorisedValue - Replace existing calls

Bug 15783: AddAuthorisedValue - Replace existing calls

The C4::Koha::AddAuthorisedValue is only called twice from
reports/guided_reports.pl and insert an authorised value.
This job can be achieve easily using the Koha::AuthorisedValue module.

Test plan:
1/ Create a new guided report
2/ Use an existing group and/or subgroup of reports
3/ Save
4/ Update an existing report
5/ Use an existing group and/or subgroup of reports
6/ Save
7/ Create or update an existing report
8/ Remove its assigned group and subgroup
9/ Save

Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com