feat(calendar): define picker UI capability

webui/src/types.ts

@@ -402,6 +402,22 @@ export type OrganizationFunctionPickerUiCapability = {
   renderLabel?: (context: OrganizationFunctionLabelContext) => ReactNode;
 };
 
+export type CalendarPickerProps = PlatformRouteContext & {
+  value: string;
+  onChange: (calendarId: string) => void;
+  id?: string;
+  name?: string;
+  label?: ReactNode;
+  emptyLabel?: ReactNode;
+  disabled?: boolean;
+  required?: boolean;
+  className?: string;
+};
+
+export type CalendarPickerUiCapability = {
+  CalendarPicker: ComponentType<CalendarPickerProps>;
+};
+
 export type MailSecurity = "plain" | "tls" | "starttls";
 export type MailProfileScope = "system" | "tenant" | "user" | "group" | "campaign";