icons: Add "plus" icon, from Figma

Taken from Figma:
  https://www.figma.com/design/1JTNtYo9memgW7vV6d0ygq/Zulip-Mobile?node-id=4912-31325&m=dev

Author: chrisbobbe

assets/icons/ZulipIcons.ttf

@@ -114,44 +114,47 @@ abstract final class ZulipIcons {
   /// The Zulip custom icon "mute".
   static const IconData mute = IconData(0xf11e, fontFamily: "Zulip Icons");
 
+  /// The Zulip custom icon "plus".
+  static const IconData plus = IconData(0xf11f, fontFamily: "Zulip Icons");
+
   /// The Zulip custom icon "read_receipts".
-  static const IconData read_receipts = IconData(0xf11f, fontFamily: "Zulip Icons");
+  static const IconData read_receipts = IconData(0xf120, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "send".
-  static const IconData send = IconData(0xf120, fontFamily: "Zulip Icons");
+  static const IconData send = IconData(0xf121, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "settings".
-  static const IconData settings = IconData(0xf121, fontFamily: "Zulip Icons");
+  static const IconData settings = IconData(0xf122, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "share".
-  static const IconData share = IconData(0xf122, fontFamily: "Zulip Icons");
+  static const IconData share = IconData(0xf123, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "share_ios".
-  static const IconData share_ios = IconData(0xf123, fontFamily: "Zulip Icons");
+  static const IconData share_ios = IconData(0xf124, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "smile".
-  static const IconData smile = IconData(0xf124, fontFamily: "Zulip Icons");
+  static const IconData smile = IconData(0xf125, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "star".
-  static const IconData star = IconData(0xf125, fontFamily: "Zulip Icons");
+  static const IconData star = IconData(0xf126, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "star_filled".
-  static const IconData star_filled = IconData(0xf126, fontFamily: "Zulip Icons");
+  static const IconData star_filled = IconData(0xf127, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "three_person".
-  static const IconData three_person = IconData(0xf127, fontFamily: "Zulip Icons");
+  static const IconData three_person = IconData(0xf128, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "topic".
-  static const IconData topic = IconData(0xf128, fontFamily: "Zulip Icons");
+  static const IconData topic = IconData(0xf129, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "topics".
-  static const IconData topics = IconData(0xf129, fontFamily: "Zulip Icons");
+  static const IconData topics = IconData(0xf12a, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "unmute".
-  static const IconData unmute = IconData(0xf12a, fontFamily: "Zulip Icons");
+  static const IconData unmute = IconData(0xf12b, fontFamily: "Zulip Icons");
 
   /// The Zulip custom icon "user".
-  static const IconData user = IconData(0xf12b, fontFamily: "Zulip Icons");
+  static const IconData user = IconData(0xf12c, fontFamily: "Zulip Icons");
 
   // END GENERATED ICON DATA
 }