* adds Ema model (basically Compensation inherited)
* adds index view for EMAs
* fixes drop-down link bug for menu 'More' in navbar
* refactors some more forms to use process_request()
* adds modified attribute to BaseResource for easy last_modified check
* adds setting of modified attribute in all places where UserAction.EDITED is added to log
* adds EMA_ACCOUNT_IDENTIFIER_LENGTH and EMA_ACCOUNT_IDENTIFIER_TEMPLATE to ema/settings.py
* adds EmaAdmin to ema/admin.py
* fixes wrong title in intervention detail view html for revocations
* adds support for subtitle variable to BaseTable and generic_index.html
* drops next_version attribute from models
* adds/updates translations
* adds default ordering for UserActionLogEntry
* removes extra ordering in log modal rendering
* 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
* adds help texts to add payment form
* adds removing button for payments
* refactors user fetching into BaseForm
* adds generic RemoveModalForm which is intended to be used for every modal form which shall remove something
* adds translations
* removes unused html
* prepares payment amount field to be able to process german inputs like '1.000,50' which is not the international default
