Add support for fetching mail label information

src/groups/mail.rs

@@ -6,3 +6,38 @@ use crate::prelude::*;
 pub struct MailGroup<'a> {
     pub(crate) esi: &'a Esi,
 }
+
+#[derive(Debug, Deserialize, Serialize, Clone)]
+/// Information about all mail labels.
+pub struct MailLabels {
+    /// List of individual mail labels.
+    pub labels: Vec<MailLabel>,
+    /// Total unread count across all labels.
+    pub unread_count: Option<i32>,
+}
+
+#[derive(Debug, Deserialize, Serialize, Clone)]
+/// Information about an individual mail label.
+pub struct MailLabel {
+    /// Color of the label as RGB Hex (`#rrggbb`).
+    pub color: String,
+    /// ID of the label.
+    pub label_id: i32,
+    /// Name of the label.
+    pub name: String,
+    /// Number of unread messages with this label.
+    #[serde(default)]
+    pub unread_count: Option<i32>,
+}
+
+impl<'a> MailGroup<'a> {
+    api_get!(
+        /// Return a list of the users mail labels, unread counts for each
+        /// label and a total unread count.
+        get_character_mail_labels,
+        "get_characters_character_id_mail_labels",
+        RequestType::Authenticated,
+        MailLabels,
+        (character_id: i32) => "{character_id}"
+    );
+}