fix: allow installation with --ignore-script

[web-padawan]

Fixes #42

The workaround is to use magi post-processing so that if user disables "postinstall" script, the export would still work. Opt-out in that case can be still done separately if needed.

So this

import './vaadin-usage-statistics-collect.js';

would become this

export * from './vaadin-usage-statistics-collect.js';

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This change is