refactor: revert assignment of oldmarr widget mapping

[Meierschlumpf]

See comment in old-import/src/widgets/definitions/index.ts

revert assignment so that only old widgets are needed in the object,
this can be done ones all widgets are implemented

Created because of #1019

[SeDemal]

packages/api/src/router/integration/integration-test-connection.ts

Same there, different reason, but to remove once all old widgets are implemented.