approvals: move post approval endpoint to /post_approvals.

Move the post approval endpoint from `POST /moderator/post/approval` to
`POST /post_approvals`.

app/views/moderator/post/queues/_quick_mod.html.erb

@@ -1,5 +1,5 @@
 <div class="quick-mod">
-  <%= link_to_if post.is_approvable?, "Approve", moderator_post_approval_path(post_id: post.id), method: :post, remote: true, class: "approve-link btn" %> |
+  <%= link_to_if post.is_approvable?, "Approve", post_approvals_path(post_id: post.id), method: :post, remote: true, class: "approve-link btn" %> |
   <%= link_to "Breaks Rules", post_disapprovals_path(post_disapproval: { post_id: post.id, reason: "breaks_rules" }), method: :post, remote: true, class: "disapprove-link btn" %> |
   <%= link_to "Poor Quality", post_disapprovals_path(post_disapproval: { post_id: post.id, reason: "poor_quality" }), method: :post, remote: true, class: "disapprove-link btn" %> |
   <%= link_to "No Interest",  post_disapprovals_path(post_disapproval: { post_id: post.id, reason: "disinterest" }), method: :post, remote: true, class: "disapprove-link btn" %> |

app/views/posts/partials/show/_options.html.erb

@@ -51,7 +51,7 @@
         <% end %>
 
         <% if post.is_approvable? && !post.is_deleted? %>
-          <li id="post-option-approve"><%= link_to "Approve", moderator_post_approval_path(post_id: post.id), remote: true, method: :post, id: "approve", "data-shortcut": "shift+o", "data-confirm": "Are you sure you want to approve this post?" %></li>
+          <li id="post-option-approve"><%= link_to "Approve", post_approvals_path(post_id: post.id), remote: true, method: :post, id: "approve", "data-shortcut": "shift+o", "data-confirm": "Are you sure you want to approve this post?" %></li>
           <li id="post-option-disapprove"><%= link_to "Hide from queue", post_disapprovals_path(post_disapproval: { post_id: post.id, reason: "disinterest" }), remote: true, method: :post, id: "disapprove" %></li>
         <% end %>