[job] enable all 'parent-…' options for parent extractors by default

- parent-directory
- parent-metadata
- parent-session
- parent-skip

- add general 'parent' option

docs/gallery-dl.conf

@@ -58,6 +58,7 @@
         "keywords-eval"     : false,
         "keywords-global"   : {},
 
+        "parent"          : false,
         "parent-directory": false,
         "parent-metadata" : false,
         "parent-session"  : false,
@@ -307,6 +308,7 @@
         "erome":
         {
             "user": {
+                "parent" : true,
                 "reposts": false
             }
         },
@@ -1023,9 +1025,8 @@
 
         "chevereto":
         {
-            "parent-metadata": true,
-            "parent-session" : true,
-            "password" : ""
+            "parent"  : true,
+            "password": ""
         },
 
         "Danbooru":
@@ -1099,8 +1100,7 @@
 
         "imagehost":
         {
-            "parent-metadata": true,
-            "parent-session" : true
+            "parent": true
         },
 
         "mastodon":