(Idea) Expose all admin components in src/admin

[robodove]

The idea of having admin ui widgets in the beta is really a nice feature

However it's very limited since we can't really customize the admin ui itself but only add widgets on top of it.

In our case we'd like to add specific attributes to the Product Entity and make them editable in the product edit form (where description etc is edited)

Just wanted to open the discussion about customizability, not just extensibility of the admin ui

Medusa could, instead of hiding away all the base admin ui, actually expose it in the starter projects and add Developer Docs on how to add them to the admin ui incrementally

E.g. i want to add multi-warehouse feature to my store
Instead of simply adding something to the config,
the docs could tell me to add:

This to the product page:

  <Admin.Product.View>
    // Admin Product Components
    <Warehouse.Admin.Product.Editable />
  </Admin.Product.View>

( and also all other relevant parts )
This would give devs also the flexibility to be creative in their approach on how to organise their admin uis while still giving medusa maintainers the ability to update the Components (and the ui) itself

This would also make it a little easier to write third-party plugins which devs can use to extend their medusa instance