Ui improvements (#5948)

* PLT-5849 - Code block wrap on IOS

* PLT-5972 - Comment has first line indented

* PLT-6048 - Adjusting UI for link previews

* PLT-5733 - Adding error text theme option

webapp/sass/layout/_forms.scss

@@ -69,8 +69,10 @@
         color: $red;
     }
 
-    .control-label {
-        color: inherit;
+    .form__label {
+        &.control-label {
+            color: inherit;
+        }
     }
 
     &.radio,

webapp/sass/layout/_webhooks.scss

@@ -46,7 +46,7 @@
             border-radius: 4px;
             border-style: solid;
             border-width: 1px;
-            margin: 0 0 5px 0;
+            margin-top: 5px;
             padding: 2px 5px;
         }
 
@@ -140,7 +140,7 @@
             &.attachment__image--openraph {
                 margin-bottom: 0;
                 max-height: 80px;
-                max-width: 200px;
+                max-width: 100%;
 
                 &.loading {
                     height: 80px;