feat(api): split api into multiple apps (#1626)

Fixes #1622

- split the api into 4 apps: core, history, schedule, storage
- exploded the settings into testing/prod

api/libretime_api/tests/runner.py

@@ -0,0 +1,23 @@
+from django.test.runner import DiscoverRunner
+
+
+class ManagedModelTestRunner(DiscoverRunner):
+    """
+    Test runner that automatically makes all unmanaged models in your Django
+    project managed for the duration of the test run, so that one doesn't need
+    to execute the SQL manually to create them.
+    """
+
+    def setup_test_environment(self, *args, **kwargs):
+        from django.apps import apps
+
+        self.unmanaged_models = [m for m in apps.get_models() if not m._meta.managed]
+        for m in self.unmanaged_models:
+            m._meta.managed = True
+        super().setup_test_environment(*args, **kwargs)
+
+    def teardown_test_environment(self, *args, **kwargs):
+        super().teardown_test_environment(*args, **kwargs)
+        # reset unmanaged models
+        for m in self.unmanaged_models:
+            m._meta.managed = False