matrix: Extend and move mjolnir's list of badwords into the vault

roles/matrix/templates/mjolnir.yaml.j2

@@ -120,7 +120,9 @@ protections:
     # of the word is present in the message in any case.  e.g. "hello" also matches
     # "HEllO".  Additionally, regular expressions can be used.
     words:
-        - "nigger"
+{% for word in vault_matrix_secrets.mjolnir_badwords %}
+      - {{ word | quote }}
+{% endfor %}
 
     # How long after a user joins the server should the bot monitor their messages.  After
     # this time, users can say words from the wordlist without being banned automatically.