- 
    Type:Feature Part 
- 
    Resolution: Done
- 
    Priority:L3 - Default 
- 
    Affects Version/s: None
- 
    Component/s: backend
In order to provide a list of possible variables all reports on the dashboard, we need a new endpoint that returns the available variables and their types for the given report Ids.
ATs:
- An endpoint exists that returns the variable names and types for the given report Ids
- API Docs are updated
API Proposal:
POST /api/variables/reports
Request Payload:
{
    "reportIds": ["reportId1", "reportId2", ...]
    // In the normal Variable names endpoint there is a namePrefix option, but we don't use this anywhere
}
Response:
[{
  name: 'name1',
  type: 'String'
}, {
  name: 'name2',
  type: 'Boolean'
}]