Add SWOT Lakes to FTS

[frankinspace]

In order to support the ability to search for identified lakes spatially, we should add a swot lakes endpoint to the FTS API.

This would be to support Use Case 2 from https://docs.google.com/document/d/1m9C-Fyy0Otar4eat28IHxbZtKIFtYshWGnFXYHHOgAE/edit?pli=1

And is related to podaac/hydrocron#133