Migrations + Cleanup

* adds needed migrations
* refactors forms.py (700+ lines) in main konova app
    * splits into forms/ and forms/modals and single class/topic-files for better maintainability and overview
* fixes bug in main konova app migration which could occur if a certain compensation migration did not run before

konova/forms/modals/base_form.py

@@ -0,0 +1,73 @@
+"""
+Author: Michel Peltriaux
+Organization: Struktur- und Genehmigungsdirektion Nord, Rhineland-Palatinate, Germany
+Contact: ksp-servicestelle@sgdnord.rlp.de
+Created on: 15.08.22
+
+"""
+from bootstrap_modal_forms.forms import BSModalForm
+from bootstrap_modal_forms.utils import is_ajax
+from django.contrib import messages
+from django.http import HttpResponseRedirect, HttpRequest
+from django.shortcuts import render
+from django.utils.translation import gettext_lazy as _
+
+from konova.contexts import BaseContext
+from konova.forms.base_form import BaseForm
+from konova.utils.message_templates import FORM_INVALID
+
+
+class BaseModalForm(BaseForm, BSModalForm):
+    """ A specialzed form class for modal form handling
+
+    """
+    is_modal_form = True
+    render_submit = True
+    template = "modal/modal_form.html"
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.action_btn_label = _("Continue")
+
+    def process_request(self, request: HttpRequest, msg_success: str = _("Object removed"), msg_error: str = FORM_INVALID, redirect_url: str = None):
+        """ Generic processing of request
+
+        Wraps the request processing logic, so we don't need the same code everywhere a RemoveModalForm is being used
+
+        Args:
+            request (HttpRequest): The incoming request
+            msg_success (str): The message in case of successful removing
+            msg_error (str): The message in case of an error
+
+        Returns:
+
+        """
+        redirect_url = redirect_url if redirect_url is not None else request.META.get("HTTP_REFERER", "home")
+        template = self.template
+        if request.method == "POST":
+            if self.is_valid():
+                if not is_ajax(request.META):
+                    # Modal forms send one POST for checking on data validity. This can be used to return possible errors
+                    # on the form. A second POST (if no errors occured) is sent afterwards and needs to process the
+                    # saving/commiting of the data to the database. is_ajax() performs this check. The first request is
+                    # an ajax call, the second is a regular form POST.
+                    self.save()
+                    messages.success(
+                        request,
+                        msg_success
+                    )
+                return HttpResponseRedirect(redirect_url)
+            else:
+                context = {
+                    "form": self,
+                }
+                context = BaseContext(request, context).context
+                return render(request, template, context)
+        elif request.method == "GET":
+            context = {
+                "form": self,
+            }
+            context = BaseContext(request, context).context
+            return render(request, template, context)
+        else:
+            raise NotImplementedError