Polish translation feature

[sdirix]

Is your feature request related to a problem? Please describe.

The i18n keys are currently definable within UI Schema options. This doesn't make much sense as merging in a default config with an i18n key is rarely a desired use case.

Describe the solution you'd like

The i18n key should be placed at the root level of the respective UI Schema element.

Describe alternatives you've considered

None

Framework

Core

RendererSet

Other (please specify in the Additional context field)

Additional context

No response