[Instantsearch] Swatch filter

[Jade-GG]

I've kept the useSwatches stuff here as there isn't really any other way to do this cleanly.

We ran into this before elsewhere recently and looked more deeply into what options we have and there really isn't much. Basically two options:

• We keep it as is, getting the swatch data with an API call and using it here. This is clean, but it requires extra functionality for something that seems like it should be quite simple.
• We could add the swatch data into the label itself and then filter it out on the frontend, which would allow us to keep all the data within ES. This would work, but it's not very clean and quite hacky.