Codelist integration

* adds codelist app
* adds KonovaCodeList and KonovaCode model for fetching and storing OSIRIS Codelisten entries
* adds update_codelist command for updating and fetching codes
* adds autocomplete route for using codelists in forms

codelist/models.py

@@ -0,0 +1,65 @@
+from django.db import models
+
+
+class KonovaCode(models.Model):
+    """
+    Representation of the OSIRIS Codelisten codes.
+
+    KonovaCodes will be updated using a command regularly to provide all codes, which are provided by the
+    Codelisten application itself. To reduce traffic, we store them in our own database.
+    """
+    id = models.IntegerField(
+        primary_key=True,
+        help_text="AtomId; Identifies this code uniquely over all NatIT projects"
+    )
+    parent = models.ForeignKey(
+        "KonovaCode",
+        on_delete=models.CASCADE,
+        null=True,
+        blank=True,
+    )
+    short_name = models.CharField(
+        max_length=500,
+        null=True,
+        blank=True,
+        help_text="Short version of long name",
+    )
+    long_name = models.CharField(
+        max_length=1000,
+        null=True,
+        blank=True,
+        help_text="",
+    )
+    is_leaf = models.BooleanField(
+        default=False,
+        help_text="Whether this code has children or not"
+    )
+    is_active = models.BooleanField(
+        default=False,
+        help_text="Whether this code is archived or not"
+    )
+
+    def __str__(self):
+        if self.is_leaf and self.parent:
+            return "{} | {}".format(self.parent.long_name, self.long_name)
+        return self.long_name
+
+
+class KonovaCodeList(models.Model):
+    """
+    The codelist itself
+    """
+    id = models.IntegerField(
+        primary_key=True,
+        help_text="List identifier",
+    )
+    codes = models.ManyToManyField(
+        KonovaCode,
+        null=True,
+        blank=True,
+        help_text="Codes for this list",
+        related_name="code_lists"
+    )
+
+    def __str__(self):
+        return str(self.id)