* adds tests for compensations (WIP)
* refactors some dummy data generating into base test class
* fixes bugs detected by testing
* adds important requirements.txt change for itsdangerous package (<1.0.0 for compatibility to django-simple-sso)
* removes unused third party package from requirements.txt
* adds KonovaSSOClient as subclass of sso.Client for more control over login, e.g. which user data shall not be updated (found in konoa/sso/sso.py)
* adds Messenger class for communicating with SSO server (found in konova/utils/messenger.py)
* adds functionality for withdraws from eco accounts in detail view of interventions and eco account as well
* adds get_surface() method to AbstractCompensation class to provide a simple getter for a sql calculation
* adds get_surface_withdraws() method to EcoAccount class to provide a simple getter for a sql calculation
* renames some routes to match coherent rout naming
* adds logic check on NewWithdrawForm
* renames templates/table directory to templates/form, since there are form-table templates inside --> more clarity
* adds new autocomplete routes to konova/urls.py for Interventions and EcoAccounts
* adds/updates translations
* adds/updates template comments
* updates requirements.txt
