stream_settings: Add stream "reset to default notifications" button.

This commit introduces a "reset to default notifications" button to
the personal panel in stream settings. On clicking, it unmutes the
current stream and resets all its notification configurations to
default user settings.

Fixes zulip#27624.

web/src/stream_edit.js

@@ -289,6 +289,25 @@ export function update_muting_rendering(sub) {
     $edit_container.find(".mute-note").toggleClass("hide-mute-note", !sub.is_muted);
 }
 
+function stream_notification_reset(e) {
+    const sub = get_sub_for_target(e.target);
+    const data = [{stream_id: sub.stream_id, property: "is_muted", value: false}];
+    for (const [per_stream_setting_name, global_setting_name] of Object.entries(
+        settings_config.generalize_stream_notification_setting,
+    )) {
+        data.push({
+            stream_id: sub.stream_id,
+            property: per_stream_setting_name,
+            value: user_settings[global_setting_name],
+        });
+    }
+
+    stream_settings_api.bulk_set_stream_property(
+        data,
+        $(`#stream_change_property_status${CSS.escape(sub.stream_id)}`),
+    );
+}
+
 function stream_is_muted_changed(e) {
     const sub = get_sub_for_target(e.target);
     if (!sub) {
@@ -537,6 +556,12 @@ export function initialize() {
         });
     });
 
+    $("#streams_overlay_container").on(
+        "click",
+        ".subsection-parent .reset-stream-notifications-button",
+        stream_notification_reset,
+    );
+
     $("#streams_overlay_container").on(
         "change",
         "#sub_is_muted_setting .sub_setting_control",

web/templates/stream_settings/stream_settings.hbs

@@ -125,6 +125,9 @@
                 <h4 class="stream_setting_subsection_title">{{t "Notification settings" }}</h4>
                 <p>{{t "In muted streams, stream notification settings apply only to unmuted topics." }}</p>
                 <div class="subsection-parent">
+                    <div class="input-group">
+                        <button class="button small rounded reset-stream-notifications-button" type="button">{{t "Reset to default notifications" }}</button>
+                    </div>
                     {{#each notification_settings}}
                         <div class="input-group">
                             {{> stream_settings_checkbox