Product Query [3]: [Variation] Hand-picked Products block

[sunyatasattva]

We want to implement Hand-picked products as a variation of the Product Query block. As of the time of writing, this is going the be the only variation of the Product Query block as it will work significantly differently. Likely all filters need to be disabled and a special input to select products should be shown. Also, there should be an easy way to custom sort the products if required. We probably want to enable users to have both custom and auto sorting orders options.

Design TBD. cc @vivialice @nerrad