There was an enhancement opened in 1.2.10 to be able to resolve multiple issues at the same time:
Enhancement ID: CSCvo79092
Enhancement Description URL: https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvo79092/?rfs=iqvred
I checked a lab instance running 1.3.3.9 and 2.1.2.5, you can mark multiple issues as resolved from the Issue dashboard in these two versions:
Assurance -> Dashboards -> Issues -> Open -> Select the checkbox for the issues in the list -> Actions -> Resolve