* Fix a spec giving false positive
* VulnerabilityFindingsActions -> ProjectVulnerabilityFindingsActions
    This captures that it contains the actions used on the project
    security dashboard
* VulnerabilityFindingsHistory -> ProjectsVulnerabilityFindingsActions
    This captures that it is/will be used on the group and instance
    security dashboards. It includes
    ProjectVulnerabilityFindingsAction and additionally adds the
    history action.
* Replace references to `group` with `vulnerable` in history cache
    classes. This reflects the upcoming use of those classes for
    the instance security dashboard.