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/safe_string.py

@@ -0,0 +1,25 @@
+import re
+import unicodedata
+
+
+def make_string_safe(string, whitespace):
+    # strips accents, diacritics etc
+    string = "".join(
+        c
+        for c in unicodedata.normalize("NFD", string)
+        if unicodedata.category(c) != "Mn"
+    )
+    string = "".join(
+        word.lower() if word.isalnum() or word == whitespace else ""
+        for word in re.sub(r"\s+", whitespace, string.strip())
+    )
+    string = re.sub(r"\.{2,}", ".", string)
+    return string.strip(".")
+
+
+def make_string_safe_for_email_local_part(string):
+    return make_string_safe(string, whitespace=".")
+
+
+def make_string_safe_for_id(string):
+    return make_string_safe(string, whitespace="-")