* changes action_type from ForeignKey into M2M
* adds migration
* changes form widget
* WIP: changes rendering on detail view of compensation
* TEST NOT CHECKED YET!
* adds support for POST of new compensations
* adds shared_users property to BaseObject and Compensation to simplify fetching of shared users (Compensation inherits from intervention)
* extends compensation admin index
* modifies compensation manager which led to invisibility of deleted entries in the admin backend
* fixes bug in sanitize_db.py where CREATED useractions would be removed if they are not found on any log but still are used on the .created attribute of the objects
* fixes bug where compensations still appeared on the public report despite being marked as deleted
* fixes bug where eco account could be deducted into a negative account balance
* optimizes the db fetching for all index views and detail views
* introduces usage of managers.py in all necessary apps for wrapping basic fetch settings
* moves comment.html to comment_card.html under /konova/templates/konova/
* adds/updates translations
* fixes document typos
* drops comment rendering in public reports
* opens public reports in new tabs if button is clicked from the detail view
