Remove AJV usage from combinator mappers

[lucas-koehler]

Direct AJV usage in renderers (i.e. oneof renderer to determine applicable sub schema) should be removed completely as this is a hacky attempt to select the suitable subschema.
In general, we want to get rid of mandatory ajv usage in general.

For combinator renderers, AJV is invoked in mapStateToCombinatorRendererProps. This should be re-written to use a heuristic instead:

• If there is an id/type/kind attribute: use to select initial entry. See if we can match this against a const in the schema. Otherwise try with first string and/or number property.
• id property should be configurable via uischema a custom JSON Schema attribute if possible. (we already use custom i18n attribute). The new attribute should start with x-jsf-. I.e. x-jsf-type-property
• allOf: Investigate whether calling mapStateToCombinatorRendererProps in mapStateToAllOfProps is necessary