FNNDSC/ChRIS_ultron_backEnd: CUBE - version 6.9.0

What's Changed Add a new computed field called active to the plugin instance serializer and filter by @jbernal0019 in https://github.com/FNNDSC/ChRIS_ultron_backEnd/pull/679 Implement the execute control for PACS queries by @jbernal0019 in https://github.com/FNNDSC/ChRIS_ultron_backEnd/pull/680 Add validation of pfcon configuration by @jbernal0019 in https://github.com/FNNDSC/ChRIS_ultron_backEnd/pull/682 Implement anonymous request to compute resources by @jbernal0019 in https://github.com/FNNDSC/ChRIS_ultron_backEnd/pull/683 Modify PACS retrieve payload to match the new UI code for PACS retrieve by @jbernal0019 in https://github.com/FNNDSC/ChRIS_ultron_backEnd/pull/688 Full Changelog: https://github.com/FNNDSC/ChRIS_ultron_backEnd/compare/v6.8.0...v6.9.0