caldav: add prop-filter support to client

caldav/caldav.go

@@ -29,9 +29,19 @@ type CalendarCompRequest struct {
 type CompFilter struct {
 	Name       string
 	Start, End time.Time
+	Props      []PropFilter
 	Comps      []CompFilter
 }
 
+type PropFilter struct {
+	Name      string
+	TextMatch *TextMatch
+}
+
+type TextMatch struct {
+	Text string
+}
+
 type CalendarQuery struct {
 	CompRequest CalendarCompRequest
 	CompFilter  CompFilter