[FEATURE] Kotlin support

[sveinnetnordic]

All my views is written in kotlin. Using kotlin for Vaadin Flow views is much better than Java, so no option to revert.

Copilot is elegant and should support kotlin. The syntax in very close to Java, just skip "new" :-)

[Artur-]

The syntax does not really matter as we parse the files into an ast and then manipulate that. Kotlin support would require a Kotlin parser and translating all rewriting operations to support that also