fix: use quote instead of quote_plus

MDQ spec explicitly asks for spaces to be encoded as %20, not +

This is achieved by urllib.parse.quote - the only difference quote_plus
brings is it would be encoding spaces as '+':
https://docs.python.org/3/library/urllib.parse.html#urllib.parse.quote_plus

While entityIDs cannot really contain spaces (not permitted in an URI),
this is all just a technicality, but quote is the correct function to use.

Author: vladimir-mencl-eresearch

src/pyff/api.py

@@ -4,7 +4,7 @@
 from datetime import datetime, timedelta
 from json import dumps
 from typing import Any, Optional
-from urllib.parse import quote_plus
+from urllib.parse import quote
 
 import pyramid.httpexceptions as exc
 import pytz
@@ -394,7 +394,7 @@ def _links(url: str, title: Any = None) -> None:
     aliases = request.registry.aliases
     for a in aliases.keys():
         for v in request.registry.md.store.attribute(aliases[a]):
-            _links(f'{a}/{quote_plus(v)}')
+            _links(f'{a}/{quote(v)}')
 
     response = Response(dumps(jrd, default=json_serializer))
     response.headers['Content-Type'] = 'application/json'

src/pyff/builtins.py

@@ -15,7 +15,7 @@
 from datetime import datetime
 from io import BytesIO
 from typing import Optional
-from urllib.parse import quote_plus, urlparse
+from urllib.parse import quote, urlparse
 
 import xmlsec
 from lxml import etree
@@ -539,7 +539,7 @@ def _nop(x):
 
     enc = _nop
     if req.args.get('urlencode_filenames'):
-        enc = quote_plus
+        enc = quote
 
     if output_file is None:
         return req.t