Generate (parts of) VSF configuration directly from the bundle

[dkarlovi]

Since Coreshop knows about the available languages (see #33), has support for multistores, currencies, etc, and this bundle will need to know directly about Elasticsearch indices (see #30), it seems there's quite a bit of knowledge which is required to create the VSF config file already available to Pimcore.

It would make sense to provide a simple command which could generate it from the available data:

1. use Pimcore's sites feature
2. use Pimcore's multilanguage feature
3. use Coreshop's stores feature
4. configure ES directly via this bundle
5. codify this into a structure VSF understands, giving a huge UX/DX win here