streams: Show "hidden" in subscriber-list when email is not accessible.

static/styles/subscriptions.css

@@ -297,6 +297,10 @@
                 top: 0;
                 z-index: 1;
             }
+
+            .hidden-subscriber-email {
+                font-style: italic;
+            }
         }
     }
 }

static/templates/stream_settings/stream_member_list_entry.hbs

@@ -2,6 +2,8 @@
     <td class="subscriber-name">{{name}}</td>
     {{#if show_email}}
     <td class="subscriber-email">{{email}}</td>
+    {{else}}
+    <td class="hidden-subscriber-email">{{t "(hidden)"}}</td>
     {{/if}}
     <td class="subscriber-user-id">{{user_id}}</td>
     {{#if displaying_for_admin}}

static/templates/stream_settings/stream_members.hbs

@@ -31,9 +31,7 @@
             <table class="subscriber-list table table-striped">
                 <thead class="table-sticky-headers">
                     <th>{{t "Name" }}</th>
-                    {{#if show_email}}
                     <th>{{t "Email" }}</th>
-                    {{/if}}
                     <th>{{t "User ID" }}</th>
                     {{#if is_realm_admin}}
                     <th class="actions">{{t "Actions" }}</th>