Refactor: save issue and project painlevel in database
Currently the pain level of the issues and the projects get calculated server-side on each render.
This is very expensive, since the workload is read-heavy (People more often load/look at the roadmap than upvote something)
We need to move the calculations in `computed.ts` into mutations, when the scores needs to be updated and save the calculations in the db.
This would also fix any inconsistencies between the public and private roadmaps
- [ ] Consider removing the score calculation entirely