Localize notification_utils to the admin

This changeset pulls in all of the notification_utils code directly into the admin and removes it as an external dependency. We are doing this to cut down on operational maintenance of the project and will begin removing parts of it no longer needed for the admin.

Signed-off-by: Carlo Costino <carlo.costino@gsa.gov>

tests/notifications_utils/test_international_billing_rates.py

@@ -0,0 +1,50 @@
+import pytest
+
+from notifications_utils.international_billing_rates import (
+    COUNTRY_PREFIXES,
+    INTERNATIONAL_BILLING_RATES,
+)
+from notifications_utils.recipients import use_numeric_sender
+
+
+def test_international_billing_rates_exists():
+    assert INTERNATIONAL_BILLING_RATES["1"]["names"][0] == "Canada"
+
+
+@pytest.mark.parametrize(
+    "country_prefix, values", sorted(INTERNATIONAL_BILLING_RATES.items())
+)
+def test_international_billing_rates_are_in_correct_format(country_prefix, values):
+    assert isinstance(country_prefix, str)
+    # we don't want the prefixes to have + at the beginning for instance
+    assert country_prefix.isdigit()
+
+    assert set(values.keys()) == {"attributes", "billable_units", "names"}
+
+    assert isinstance(values["billable_units"], int)
+    assert 1 <= values["billable_units"] <= 3
+
+    assert isinstance(values["names"], list)
+    assert all(isinstance(country, str) for country in values["names"])
+
+    assert isinstance(values["attributes"], dict)
+    assert values["attributes"]["dlr"] is None or isinstance(
+        values["attributes"]["dlr"], str
+    )
+
+
+def test_country_codes():
+    assert len(COUNTRY_PREFIXES) == 214
+
+
+@pytest.mark.parametrize(
+    "number, expected",
+    [
+        ("+48123654789", False),  # Poland alpha: Yes
+        ("+1-403-123-5687", True),  # Canada alpha: No
+        ("+40123548897", False),  # Romania alpha: REG
+        ("+60123451345", True),
+    ],
+)  # Malaysia alpha: NO
+def test_use_numeric_sender(number, expected):
+    assert use_numeric_sender(number) == expected