judging, hq: judge refactor

• cleanup duplicated ZoomIcon
• refactor judging models (stats, progress, availabilities) to match hq-tech/backend!279 (merged)
• create TableHeader component for HQ tools, to remove duplicated code and increase consistency
• standardise organisation and display of table filters, overview and buttons
• remove HQ > Jamboree > Judges pages. Tickets can display the same info for Jamboree staff. Judges can display the same info for Judging staff.
• create TimeTooltipCell to facilitate displaying datetime in tables
• standardise function declarations as function XX (): returnType instead of const XX = () =>, the first being more explicit (we don't declare strings as const text = () => "lalala")
• standardise exports, we had both default and explicit forms. Explicit form creates more consistency, as several components had different names when imported (ActivityLog.tsx => ActivityLogComponent => ActiityLog, similar to several forms)

TimeTooltipCell utilisation: