Add filter for favorited sessions on conf schedule page

[AgentEnder]

Is your feature request related to a problem? Please describe.
When looking at the conference schedule I would like to be able to easily toggle filtering by favorited sessions. While the favorites page exists, its not where I'm typically looking when looking for that day's sessions.

Describe the solution you'd like
Inside the filter dropdown, add a checkbox to toggle filtering by favorites

Describe alternatives you've considered
A link to the existing favorites page could also work

Additional context
Add any other context or screenshots about the feature request here.