Compensation forms refactoring

* splits compensation/forms.py and /modalForms.py into individual files inside new packages
    * general forms stay in new files in compensation/forms
    * modal forms stay in new files in compensation/forms/modals

ema/forms.py

@@ -10,8 +10,8 @@ from django.db import transaction
 from django.urls import reverse, reverse_lazy
 from django.utils.translation import gettext_lazy as _
 
-from compensation.forms.forms import AbstractCompensationForm, CompensationResponsibleFormMixin, \
-    PikCompensationFormMixin
+from compensation.forms.mixins import CompensationResponsibleFormMixin, PikCompensationFormMixin
+from compensation.forms.compensation import AbstractCompensationForm
 from ema.models import Ema, EmaDocument
 from intervention.models import Responsibility, Handler
 from konova.forms import SimpleGeomForm