Remove Hybrid Selection, Simplify to: Virtual, In-person, Virtual+In-person

As a user, I would expect hybrid positions to be included in search results for positions that are set as In-person, because hybrid positions are functionally in-person (as well as virtual).

Instead, the current logic separates Hybrid as its own category, so that all Hybrid, In-person, and Virtual positions are mutually-exclusive-cumulatively-exhaustive. I don't like this because when I'm looking for positions by In-person, hybrid positions are excluded from those results. I think Hybrid should be removed from the logic and simply use In-person and Virtual, where positions are all either:

1. Virtual

2. In-person

3. Virtual & In-person (aka Hybrid)

This simplification would still express the same information, while also allowing for hybrid positions to be included in searches for In-person positions.

And ideally the Volunteer Type filter will be adjusted to enable multi-select, so that any user seeking hybrid positions specifically could select both Virtual and In-person.