refactor: Fix note trigger upon sharing revocation

  Don't wait until the user tries to open a note from a revoked sharing
  to recreate its trigger but do it instead upon the sharing revocation.

model/sharing/files.go

@@ -701,6 +701,12 @@ func (s *Sharing) FixRevokedNotes(inst *instance.Instance) error {
 
 	var errm error
 	for _, doc := range docs {
+		// If the note came from another cozy via a sharing that is now revoked, we
+		// may need to recreate the trigger.
+		if err := note.SetupTrigger(inst, doc.ID()); err != nil {
+			errm = multierror.Append(errm, fmt.Errorf("failed to setup revoked note trigger: %w", err))
+		}
+
 		if err := note.ImportImages(inst, doc); err != nil {
 			errm = multierror.Append(errm, fmt.Errorf("failed to import revoked note images: %w", err))
 		}

model/sharing/open_note.go

@@ -81,6 +81,9 @@ func (o *NoteOpener) GetResult(memberIndex int, readOnly bool) (jsonapi.Object,
 func (o *NoteOpener) openLocalNote(memberIndex int, readOnly bool) (*apiNoteURL, error) {
 	// If the note came from another cozy via a sharing that is now revoked, we
 	// may need to recreate the trigger.
+	// This should be taken care of when revoking the sharing now but we leave
+	// this call to make sure notes from previously revoked sharings will
+	// continue to work.
 	_ = note.SetupTrigger(o.Inst, o.File.ID())
 
 	code, err := o.GetSharecode(memberIndex, readOnly)