Allow to round taxes on order-level (#5019)

* Allow to round taxes on order-level

* Rename get_cart_total

* Persist rounding mode with order

* Add general docs

* Order creation API

* Update fee algorithm

* Rounding on payment method change

* Round when splitting order

* Fix failing tests

* Add settings page

* Add tests

* Replace algorithm

* Add test case for currency rounding

* Improve order change

* Update flowchart

* Update discount logic (more hypothetical, we don't store rounding on cart positions atm)

* Rename internal method

* Fix typo

* Update help text

* Apply suggestions from code review

Co-authored-by: luelista <weller@rami.io>

* Order rounding refactor (#5571)

* Add RoundingCorrectionMixin providing before-rounding-values as properties

* Use gross_price_before_rounding in more places

* Update doc/development/algorithms/pricing.rst

Co-authored-by: Martin Gross <gross@rami.io>

* Allow to override on perform_order

* Rebase migration

* Fix event cancellation

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Co-authored-by: luelista <weller@rami.io>
Co-authored-by: Martin Gross <gross@rami.io>

src/pretix/control/urls.py

@@ -290,7 +290,7 @@ urlpatterns = [
         re_path(r'^settings/invoice$', event.InvoiceSettings.as_view(), name='event.settings.invoice'),
         re_path(r'^settings/invoice/preview$', event.InvoicePreview.as_view(), name='event.settings.invoice.preview'),
         re_path(r'^settings/display', event.DisplaySettings.as_view(), name='event.settings.display'),
-        re_path(r'^settings/tax/$', event.TaxList.as_view(), name='event.settings.tax'),
+        re_path(r'^settings/tax/$', event.TaxSettings.as_view(), name='event.settings.tax'),
         re_path(r'^settings/tax/(?P<rule>\d+)/$', event.TaxUpdate.as_view(), name='event.settings.tax.edit'),
         re_path(r'^settings/tax/add$', event.TaxCreate.as_view(), name='event.settings.tax.add'),
         re_path(r'^settings/tax/(?P<rule>\d+)/delete$', event.TaxDelete.as_view(), name='event.settings.tax.delete'),