Add default theme for browser tests

..._jwt/tests/src/FunctionalJavascript/SalesforceJwtTest.php

modules/salesforce_mapping/src/Entity/MappedObject.php

...alesforce_mapping/tests/src/Functional/PushParamsTest.php

...ce_mapping_ui/src/Tests/SalesforceMappingCrudFormTest.php

...th/tests/src/FunctionalJavascript/SalesforceOAuthTest.php

...es/salesforce_pull/tests/src/Functional/PullQueueTest.php

modules/salesforce_pull/tests/src/Unit/DeleteHandlerTest.php

...es/salesforce_push/tests/src/Functional/PushQueueTest.php

tests/src/Functional/StatusPageTest.php