Fix posts counts in workspace panel

Summary:
- Show post counts for total and unpublished
- Filter post counts by type=report

Test Plan:
Load homepage
Check post counts appear in workspace menu
Check post counts match the counts shown above listings

Reviewers: aMoniker, shadowhand

Reviewed By: shadowhand

Maniphest Tasks: T432

Differential Revision: https://phabricator.ushahidi.com/D380