message_history: Improve overlay header.

If users are only allowed to view move history, the header
is 'Message move history.' If users are allowed to view edit
and move history and the message is edited and moved, the header
is 'Message edit and move history.' Otherwise, it shows 'Message
edit history.' If the message is only moved (and not edited), it
shows 'Message move history.'

Fixes #34005.

web/src/message_edit_history.ts

@@ -114,11 +114,18 @@ function hide_loading_indicator(): void {
 }
 
 export function fetch_and_render_message_history(message: Message): void {
+    assert(message_lists.current !== undefined);
+    const message_container = message_lists.current.view.message_containers.get(message.id);
+    assert(message_container !== undefined);
     const move_history_only =
         realm.realm_message_edit_history_visibility_policy ===
         message_edit_history_visibility_policy_values.moves_only.code;
     $("#message-edit-history-overlay-container").html(
-        render_message_history_overlay({move_history_only}),
+        render_message_history_overlay({
+            moved: message_container.moved,
+            edited: message_container.edited,
+            move_history_only,
+        }),
     );
     open_overlay();
     show_loading_indicator();

web/templates/message_history_overlay.hbs

@@ -5,8 +5,16 @@
                 {{#if move_history_only}}
                 <h1>{{t "Message move history" }}</h1>
                 {{else}}
+                {{#if edited}}
+                    {{#if moved}}
+                    <h1>{{t "Message edit and move history" }}</h1>
+                    {{else}}
                     <h1>{{t "Message edit history" }}</h1>
                     {{/if}}
+                {{else if moved}}
+                    <h1>{{t "Message move history" }}</h1>
+                {{/if}}
+                {{/if}}
                 <div class="exit">
                     <span class="exit-sign">&times;</span>
                 </div>