FIX: Mobile usability issues in crawler view (#17465)

Google is complaining about some mobile crawler layout issues. If a post has tables, they extend outside the viewport.

<img height="300" src="https://user-images.githubusercontent.com/33972521/178642976-3d1761ad-d8cb-4c69-92b5-7be799873d5c.png">

This PR fixes that. We constrain the post to the viewport width (already determined from a parent element) and make it possible to scroll instead. 

There is no visual change here, it should act the same as it does today, but it makes Google happy.

This PR also adds a bit of margin to tags in the `/tags` page in the crawler view because Google was complaining about `Clickable elements too close together`

<img height="300" src="https://user-images.githubusercontent.com/33972521/178644327-cc3ff795-24f1-4fef-95c9-e4358a5b37bc.png">

app/assets/stylesheets/common/base/crawler_layout.scss

@@ -144,6 +144,8 @@ body > noscript {
   div#main-outlet {
     div.post {
       word-break: break-word;
+      overflow: auto;
+      max-width: 100%;
       img {
         max-width: 100%;
         height: auto;
@@ -195,6 +197,12 @@ body > noscript {
     }
   }
 
+  .tag-crawler {
+    .tag-box {
+      margin-bottom: 0.5em;
+    }
+  }
+
   #topic-title {
     > * {
       display: block;