move CurrencyField to counter

counter/fields.py

@@ -0,0 +1,30 @@
+from decimal import Decimal
+
+from django.conf import settings
+from django.db import models
+
+
+class CurrencyField(models.DecimalField):
+    """Custom database field used for currency."""
+
+    def __init__(self, *args, **kwargs):
+        kwargs["max_digits"] = 12
+        kwargs["decimal_places"] = 2
+        super().__init__(*args, **kwargs)
+
+    def to_python(self, value):
+        if value is None:
+            return None
+        return super().to_python(value).quantize(Decimal("0.01"))
+
+
+if settings.TESTING:
+    from model_bakery import baker
+
+    baker.generators.add(
+        CurrencyField,
+        lambda: baker.random_gen.gen_decimal(max_digits=8, decimal_places=2),
+    )
+else:  # pragma: no cover
+    # baker is only used in tests, so we don't need coverage for this part
+    pass