(Bug 58991) Enable listed SpecialPages for InternalParseBeforeLinks hook (incl. SMW\ContentProcessor)

https://bugzilla.wikimedia.org/show_bug.cgi?id=58991

Adds $smwgEnabledSpecialPage and can be used to pages like RunQuery etc.

### Default
$GLOBALS['smwgEnabledSpecialPage'] = array( 'Ask' );

### SMW + SF related settings
$GLOBALS['smwgEnabledSpecialPage'] = array( 'Ask', 'RunQuery' );