EMA

* 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

ema/models.py

@@ -0,0 +1,74 @@
+from django.contrib.auth.models import User
+from django.db import models
+
+from compensation.models import AbstractCompensation
+from konova.settings import DEFAULT_SRID_RLP, LANIS_LINK_TEMPLATE
+from user.models import UserActionLogEntry
+
+
+class Ema(AbstractCompensation):
+    """
+    EMA = Ersatzzahlungsmaßnahme
+    (compensation actions from payments)
+
+    Until 2015 the EMA was the data object to keep track of any compensation, which has been funded by payments
+    previously paid. In 2015 another organization got in charge of this, which led to the creation of the data object
+    MAE (which is basically the same, just renamed in their system) to differ between the 'old' payment funded ones and
+    the new. For historical reasons, we need to keep EMAs in our system, since there are still entries done to this day,
+    which have been performed somewhere before 2015 and therefore needs to be entered.
+    Further information:
+    https://snu.rlp.de/de/foerderungen/massnahmen-aus-ersatzzahlungen/uebersicht-mae/
+
+    EMA therefore holds data like a compensation: actions, before-/after-states, deadlines, ...
+
+    """
+    # Users having access on this object
+    # Not needed in regular Compensation since their access is defined by the linked intervention's access
+    users = models.ManyToManyField(
+        User,
+        help_text="Users having access (shared with)"
+    )
+
+    # Refers to "verzeichnen"
+    recorded = models.OneToOneField(
+        UserActionLogEntry,
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        help_text="Holds data on user and timestamp of this action",
+        related_name="+"
+    )
+
+    def __str__(self):
+        return "{}".format(self.identifier)
+
+    def save(self, *args, **kwargs):
+        if self.identifier is None or len(self.identifier) == 0:
+            # Create new identifier
+            new_id = self._generate_new_identifier()
+            while Ema.objects.filter(identifier=new_id).exists():
+                new_id = self._generate_new_identifier()
+            self.identifier = new_id
+        super().save(*args, **kwargs)
+
+    def get_LANIS_link(self) -> str:
+        """ Generates a link for LANIS depending on the geometry
+
+        Returns:
+
+        """
+        try:
+            geom = self.geometry.geom.transform(DEFAULT_SRID_RLP, clone=True)
+            x = geom.centroid.x
+            y = geom.centroid.y
+            zoom_lvl = 16
+        except AttributeError:
+            # If no geometry has been added, yet.
+            x = 1
+            y = 1
+            zoom_lvl = 6
+        return LANIS_LINK_TEMPLATE.format(
+            zoom_lvl,
+            x,
+            y,
+        )