Add relevant_orderlist exporter (including bugfixes)

This Exporter has the most useful information in the first rows of the
exported document. Specifically the product and the custom questions.
Other fields are also resorted somewhat to place very useless columns at
the end of the table. See code for details :)
- register relevant_orderlist as separate data_exporter
- sort it with the other order data exporters.

src/pretix/base/exporters/__init__.py

@@ -28,5 +28,6 @@ from .items import *  # noqa
 from .json import *  # noqa
 from .mail import *  # noqa
 from .orderlist import *  # noqa
+from .relevant_orderlist import *  # noqa
 from .reusablemedia import *  # noqa
 from .waitinglist import *  # noqa

src/pretix/base/exporters/orderlist.py

@@ -88,7 +88,7 @@ class OrderListExporter(MultiSheetListExporter):
     description = gettext_lazy('Download a spreadsheet of all orders. The spreadsheet will include three sheets, one '
                                'with a line for every order, one with a line for every order position, and one with '
                                'a line for every additional fee charged in an order.')
-    featured = True
+    featured = False
 
     @cached_property
     def providers(self):