feat: add a command to import dashboards (#11749)

* feat: add a command to import dashboards

* Fix lint

* Remove print()

tests/databases/commands_tests.py

@@ -279,6 +279,8 @@ class TestExportDatabasesCommand(SupersetTestCase):
             "version",
         ]
 
+
+class TestImportDatabasesCommand(SupersetTestCase):
     def test_import_v1_database(self):
         """Test that a database can be imported"""
         contents = {