refactor: move month_year_picker to common and make it more generic

app/apps/monthly_overview/urls.py

@@ -19,9 +19,4 @@ urlpatterns = [
         views.monthly_summary,
         name="monthly_summary",
     ),
-    path(
-        "available_dates/",
-        views.month_year_picker,
-        name="available_dates",
-    ),
 ]

app/apps/monthly_overview/views.py

@@ -2,10 +2,6 @@ from decimal import Decimal
 
 from django.contrib.auth.decorators import login_required
 from django.db.models import (
-    Case,
-    When,
-    Value,
-    IntegerField,
     Sum,
     Q,
 )

app/apps/monthly_overview/views/__init__.py

@@ -1,2 +0,0 @@
-from .ui import *
-from .main import *