Bug 12001: Move GetMemberAccountBalance to Koha::Account->non_issues_charges

Bug 12001: Move GetMemberAccountBalance to Koha::Account->non_issues_charges

As said previously, GetMemberAccountBalance returns ( the balance, the
non issues charges, the other charges)

The other charges are the balance - the non issues charges.

In this patch we remove the subroutine from C4::Members and use the
new Koha::Account->non_issues_charges subroutine instead

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>