Move ical-related stuff to rustical_ical crate

crates/store/src/addressbook.rs

@@ -0,0 +1,20 @@
+use crate::synctoken::format_synctoken;
+use chrono::NaiveDateTime;
+use serde::Serialize;
+
+#[derive(Debug, Clone, Serialize)]
+pub struct Addressbook {
+    pub id: String,
+    pub principal: String,
+    pub displayname: Option<String>,
+    pub description: Option<String>,
+    pub deleted_at: Option<NaiveDateTime>,
+    pub synctoken: i64,
+    pub push_topic: String,
+}
+
+impl Addressbook {
+    pub fn format_synctoken(&self) -> String {
+        format_synctoken(self.synctoken)
+    }
+}