Add data migration 0.7 -> 0.8

Close #809. Fix #746
Add flymake targets
Remove some api endpoints that are redundant
Some cleanup
Api should have it's own coordinator interface
more cleanup
Don't overuse interfaces if there's no benefit
Use GetQueryString() instead of accessing the internal field
Fix parsing of multiple queries
Use the client instead of manually posting to the server
Rename
Add a coordinator interface in the migration package