Add missing re-exports and vars to requests.compat (#8396)

stubs/requests/requests/compat.pyi

@@ -1,3 +1,18 @@
-import collections
+from collections import OrderedDict as OrderedDict
+from urllib.parse import (
+    quote as quote,
+    quote_plus as quote_plus,
+    unquote as unquote,
+    unquote_plus as unquote_plus,
+    urldefrag as urldefrag,
+    urlencode as urlencode,
+    urljoin as urljoin,
+    urlparse as urlparse,
+    urlsplit as urlsplit,
+    urlunparse as urlunparse,
+)
+from urllib.request import getproxies as getproxies, parse_http_list as parse_http_list, proxy_bypass as proxy_bypass
 
-OrderedDict = collections.OrderedDict
+is_py2: bool
+is_py3: bool
+has_simplejson: bool