Extend support for sharing filters and dashboards to include shares with users and view/edit permissions

JIRA 7.12 extends the share system for filters and dashboards in two ways:

• It becomes possible to share an item with a specific user
• Each share can specify if the recipient is allowed to edit or view the filter/dashboard

Project Configurator must support these new features in 7.12, including:

• Accepting pre-7.12 configurations in JIRA 7.12 with sensible defaults.
• When applying 7.12 configurations to a pre-7.12 instance the new features should be ignored and not break the import. Ideally a warning should be issued to let the user know about this (inevitable) loss.