[skeb] implement 'include' option (#6558 #7267)

- split 'user' extractor into 'works' & 'sent-requests' extractors
- use BASE_PATTERN & USER_PATTERN
- use self.groups

docs/configuration.rst

@@ -4746,6 +4746,28 @@ Description
     Download article images.
 
 
+extractor.skeb.include
+----------------------
+Type
+    * ``string``
+    * ``list`` of ``strings``
+Default
+    ``"works"``
+Example
+    * ``"works,sent-requests"``
+    * ``["works", "sent-requests"]``
+Description
+    A (comma-separated) list of subcategories to include
+    when processing a user profile.
+
+    Possible values are
+
+    * ``"works"``
+    * ``"sent-requests"``
+
+    It is possible to use ``"all"`` instead of listing all values separately.
+
+
 extractor.skeb.sent-requests
 ----------------------------
 Type