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):

src/pretix/locale/de/LC_MESSAGES/django.po

@@ -1821,6 +1821,10 @@ msgstr "Ohne gültige Mitgliedschaft verstecken"
 msgid "Order data"
 msgstr "Bestelldaten"
 
+#: pretix/base/exporters/relevant_orderlist.py:86
+msgid "Order data (sorted by relevance)"
+msgstr "Bestelldaten (nach Relevanz sortiert)"
+
 #: pretix/base/exporters/json.py:53
 msgid ""
 "Download a structured JSON representation of all orders. This might be "
@@ -1857,6 +1861,18 @@ msgstr ""
 "Bestellposition und das dritte eine Zeile für jede zusätzlich erhobene "
 "Gebühr."
 
+#: pretix/base/exporters/relevant_orderlist.py:88
+msgid ""
+"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. The most relevant data is in the first columns of the tables."
+msgstr ""
+"Tabelle (Excel oder CSV) mit allen Bestellungen. Das erste Tabellenblatt "
+"enthält eine Zeile für jede Bestellung, das zweite eine Zeile für jede "
+"Bestellposition und das dritte eine Zeile für jede zusätzlich erhobene "
+"Gebühr. Die relevantesten Daten sind in den ersten Spalten der Tabellen."
+
 #: pretix/base/exporters/orderlist.py:100 pretix/base/models/orders.py:332
 #: pretix/control/navigation.py:255 pretix/control/navigation.py:362
 #: pretix/control/templates/pretixcontrol/orders/index.html:8