Added empty state handling to email debug tabs

refs. https://github.com/TryGhost/Team/issues/2327

- the lists and tables were completely empty when there was no error or some data was missing

ghost/admin/app/components/posts/debug.hbs

@@ -91,6 +91,13 @@
                     </div>
                 </tr>
                 {{/each}}
+                {{#unless this.permanentFailureData}}
+                <tr>
+                    <td>
+                        <div class="gh-email-debug-empty-list">No permanent failures.</div>    
+                    </td>
+                </tr>
+                {{/unless}}
                 {{!-- <tr>
                     <div class="gh-list-data gh-email-debug-col-member">
                         <div class="gh-email-debug-member">
@@ -223,6 +230,13 @@
                     </div>
                 </tr>
                 {{/each}}
+                {{#unless this.temporaryFailureData}}
+                <tr>
+                    <td>
+                        <div class="gh-email-debug-empty-list">No temporary failures.</div>    
+                    </td>
+                </tr>
+                {{/unless}}
                 {{!-- <tr>
                     <div class="gh-list-data gh-email-debug-col-member">
                         <div class="gh-email-debug-member">
@@ -313,6 +327,8 @@
                         <div class="gh-list-data gh-email-debug-batch-col-segment">
                             {{#if batch.segment}}
                                 <span>{{batch.segment}}</span>
+                            {{else}}
+                                <div class="dib lightgrey">N/A</div>
                             {{/if}}
                         </div>
                         <div class="gh-list-data gh-email-debug-batch-col-recipients">
@@ -320,6 +336,7 @@
                         </div>
                         <div class="gh-list-data gh-email-debug-batch-col-details">
                             <div class="flex flex-col items-center space-between w100">
+                                {{#if (or batch.providerId batch.errorStatusCode batch.errorMessage)}}
                                     <div class="detailtext">
                                         {{#if batch.providerId}}
                                         <div>Provider id:
@@ -340,6 +357,9 @@
                                     {{#if batch.errorMessage}}
                                     <div class="download-icon">{{svg-jar "download" title="Download full failure message"}}</div>
                                     {{/if}}
+                                {{else}}
+                                    <div class="dib lightgrey">N/A</div>
+                                {{/if}}
                             </div>
                         </div>
                     </tr>

ghost/admin/app/styles/layouts/settings.css

@@ -3413,3 +3413,10 @@ p.theme-validation-details {
 .gh-email-debug-settings-icon .x path {
     stroke: var(--midgrey);
 }
+
+.gh-email-debug-empty-list {
+    margin: 120px 40px;
+    text-align: center;
+    font-size: 1.3rem;
+    color: var(--midgrey);
+}