Automate code start updates

[mcollovati]

Currently, to update codestart there's a maven profile running the HillaAppInitUtility class to generate up-to-date resources.
However, Hilla removed the class, so the process is not working anymore.

We need to find an alternative way to update the code start code.
Some tools we can consider:

• npm init vaadin@latest
• download from https://start.vaadin.com/dl?preset=base,partial-hilla-example-views&projectName=qh-codestart (base,hilla for Lit)

[mcollovati]

Implemented in #1279 by commit 30e6dec