Allow filtering to type of vaccine

[livgust]

Some people are looking to book their second appointment and have to find one for the same vaccine manufacturer as their first appointment.

This would likely mean an update to the back-end scrapers to ensure that they pass that information if available.

If we add enough filters and sorters, we likely will want some kind of gear or menu for filters so they don't clutter the page.

[linusmarco]

I'm working on this one. Should have a PR in this weekend. As part of this I'm doing a little refactor to group all filters into a component t separate from the main site list.