refactor(quark): port get/set_settings, get_unreads

#283

crates/core/models/src/v0/user_settings.rs

@@ -1,6 +1,26 @@
+#[cfg(feature = "rocket")]
+use rocket::FromForm;
+
 use std::collections::HashMap;
 
 /// HashMap of user settings
 /// Each key is mapped to a tuple consisting of the
 /// revision timestamp and serialised data (in JSON format)
 pub type UserSettings = HashMap<String, (i64, String)>;
+
+auto_derived!(
+    /// Options for fetching settings
+    pub struct OptionsFetchSettings {
+        /// Keys to fetch
+        pub keys: Vec<String>,
+    }
+
+    /// Additional options for inserting settings
+    #[cfg_attr(feature = "rocket", derive(FromForm))]
+    pub struct OptionsSetSettings {
+        /// Timestamp of settings change.
+        ///
+        /// Used to avoid feedback loops.
+        pub timestamp: Option<i64>,
+    }
+);