Introduce new Pickup locations block.

[senadir]

As of right now, Shipping options block would only render shipping rates, we want to introduce a new pickup locations block that renders pickup locations, the benefit here is that it would have its own inner block area to render pickup location specific data. The main different is that you can click to expand a rate.

In the editor, Local pickup will be a sibling of shipping options, both will be rendered inside a block that has view switching capabilities, this is to be tackled in another PR.