List Google events or Apple events and recurring series, upcoming by default, 50 per page

Required calendarId query. Up to 50 Google events or Apple events and recurring series, upcoming by default. Optional search, timeMin, timeMax and pageToken. Time bounds need offsets. Continue with nextPageToken and identical filters, including a fixed timeMin. Apple recurring:true identifies a whole series; its start/end describe the original occurrence, and updates change the series master while preserving individual exceptions. An unknown query parameter is rejected with 400 validation here - unlike the rest of v1, extra parameters are not ignored.