[team-schedule] Add department filter and anonymous busy blocks

[frankrousseau]

Problem

• The team schedule offered no department scoping for supervisors, and artists booked on other productions appeared free (fixes As supervisor and production manager, the Team Schedule page is not filtered according to our department / production. #1579).
• The onion skin picker had a misplaced v-for.

Solution

• Department combo gets the All / My departments options, defaulting to My departments for supervisors; the people list filters on department lists.
• The anonymous busy_periods served by zou render as inert grey "Busy on another production" bars on expanded rows and extend the person's root bar.
• Move the v-for to the right node in OnionSkinPicker.