Localize notification_utils to the API

This changeset pulls in all of the notification_utils code directly into the API 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 API.

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

notifications_utils/countries/__init__.py

@@ -0,0 +1,81 @@
+from functools import lru_cache
+
+from notifications_utils.insensitive_dict import InsensitiveDict
+from notifications_utils.sanitise_text import SanitiseASCII
+
+from .data import (
+    ADDITIONAL_SYNONYMS,
+    COUNTRIES_AND_TERRITORIES,
+    EUROPEAN_ISLANDS,
+    ROYAL_MAIL_EUROPEAN,
+    UK,
+    UK_ISLANDS,
+    WELSH_NAMES,
+    Postage,
+)
+
+
+class CountryMapping(InsensitiveDict):
+    @staticmethod
+    @lru_cache(maxsize=2048, typed=False)
+    def make_key(original_key):
+        original_key = original_key.replace("&", "and")
+        original_key = original_key.replace("+", "and")
+
+        normalised = "".join(
+            character.lower()
+            for character in original_key
+            if character not in " _-'’,.()"
+        )
+
+        if "?" in SanitiseASCII.encode(normalised):
+            return normalised
+
+        return SanitiseASCII.encode(normalised)
+
+    def __contains__(self, key):
+        if any(c.isdigit() for c in key):
+            # A string with a digit can’t be a country and is probably a
+            # postcode, so let’s do a little optimisation, skip the
+            # expensive string manipulation to normalise the key and say
+            # that there’s no matching country
+            return False
+        return super().__contains__(key)
+
+    def __getitem__(self, key):
+        for key_ in (key, f"the {key}", f"yr {key}", f"y {key}"):
+            if key_ in self:
+                return super().__getitem__(key_)
+
+        raise CountryNotFoundError(f"Not a known country or territory ({key})")
+
+
+countries = CountryMapping(
+    dict(
+        COUNTRIES_AND_TERRITORIES
+        + UK_ISLANDS
+        + EUROPEAN_ISLANDS
+        + WELSH_NAMES
+        + ADDITIONAL_SYNONYMS
+    )
+)
+
+
+class Country:
+    def __init__(self, given_name):
+        self.canonical_name = countries[given_name]
+
+    def __eq__(self, other):
+        return self.canonical_name == other.canonical_name
+
+    @property
+    def postage_zone(self):
+        if self.canonical_name == UK:
+            return Postage.UK
+        if self.canonical_name in ROYAL_MAIL_EUROPEAN:
+            return Postage.EUROPE
+        return Postage.REST_OF_WORLD
+
+
+class CountryNotFoundError(KeyError):
+    pass