feat(remind): implement alarm rendering for triggers

Remove debug logging from `collect_triggers` and
`separate_master_and_recurrence`, and add full alarm rendering support:
convert `Timedesc.Span.t` triggers to `++n`/`WARN`/`+n`/`SCHED` remind
syntax for both all-day and timed events, with dynamic `FSET` generation
for multiple triggers and annotated `MSG` bodies showing advance notice.

bin/utils.ml

@@ -258,7 +258,6 @@ let get_conference_url ev =
     ev.props
 
 let separate_master_and_recurrence (events : Icalendar.event list) : Icalendar.event * Icalendar.event list =
-  (* List.iteri (fun i e -> Printf.eprintf "%02d: %s\n" (i + 1) (Icalendar.show_component (`Event e))) events; *)
   let recur_ids = List.map (fun ev -> (ev, get_recurrence_id ev)) events in
 
   let master_and_recurrences =