Add support for Java Records

[mstahv]

This could be achieved by e.g. using FormBinder (from in.virit:viritin) instead of the Binder in Vaadin core. One would also get proper crossfield validation (aka class level validatorsupport). Haven't yet investigated how big of a renewal this would be, but a new major version would at least be needed as Binder seems to be exposed as API.