feat(bookings): allow transferring bookings to another PIC

Add UI modal and button to reassign bookings to different contacts
Create API endpoint and repository method to handle PIC transfers

shared/booking.ts

@@ -150,6 +150,10 @@ export interface CancelBookingConfirmationResponse {
   alreadyPending: boolean
 }
 
+export interface TransferBookingPicResponse {
+  booking: PublicBooking
+}
+
 export function isBookingStatus(value: string | null | undefined): value is BookingStatus {
   return value === 'pending' || value === 'confirmed'
 }