Implement payment backends and interaction

Advances #3 (closed)

aleksis/apps/tezor/menus.py

-from django.utils.translation import gettext_lazy as _
-
-MENUS = {
-    "NAV_MENU_CORE": [
-        {
-            "name": _("Tezor"),
-            "url": "empty",
-            "root": True,
-            "validators": [
-                "menu_generator.validators.is_authenticated",
-                "aleksis.core.util.core_helpers.has_person",
-            ],
-            "submenu": [],
-        }
-    ]
-}