Fix comment triangles and tweak inline comment margins (#13554)

- Fix various miscolored comment bubble triangles
- Tweak padding on inline comment boxes

web_src/less/_review.less

@@ -42,11 +42,15 @@
 }
 
 .comment-code-cloud {
-  padding: 4px;
+  padding: .5rem;
   padding-left: 0;
   position: relative;
   margin: 0 auto;
 
+  .comments .comment {
+    margin: 0;
+  }
+
   .attached {
     &.tab {
       border: 0;