Fix #4669: Track moderation report status.

* Add ability to mark moderation reports as 'handled' or 'rejected'.
* Automatically mark reports as handled when the comment or forum post
  is deleted.
* Send a dmail to the reporter when their report is handled.
* Don't show the report notice on comments or forum posts when all
  reports against it have been handled or rejected.
* Add a fix script to mark all existing reports for deleted comments,
  forum posts, or dmails as handled.

app/views/moderation_reports/index.html.erb

@@ -7,6 +7,7 @@
       <%= f.input :reason_matches, label: "Reason", input_html: { value: params[:search][:reason_matches] } %>
       <%= f.input :model_id, label: "ID", input_html: { value: params[:search][:model_id] } %>
       <%= f.input :model_type, label: "Type", collection: ModerationReport.model_types, include_blank: true, selected: params[:search][:model_type] %>
+      <%= f.input :status, label: "Status", collection: ModerationReport.statuses.keys, include_blank: true, selected: params[:search][:status] %>
       <%= f.submit "Search" %>
     <% end %>
 
@@ -26,6 +27,10 @@
         </span>
       <% end %>
 
+      <% t.column "Status" do |report| %>
+        <%= link_to report.status.capitalize, moderation_reports_path(search: { status: report.status }) %>
+      <% end %>
+
       <% t.column "Reported user" do |report| %>
         <%= link_to_user report.reported_user %>
       <% end %>
@@ -35,6 +40,18 @@
         <%= link_to "»", moderation_reports_path(search: { creator_name: report.creator.name }) %>
         <div><%= time_ago_in_words_tagged(report.created_at) %></div>
       <% end %>
+
+      <% t.column column: "control" do |report| %>
+        <%= render PopupMenuComponent.new do |menu| %>
+          <% menu.item do %>
+            <%= link_to "Mark as handled", moderation_report_path(report.id), method: :put, remote: true, "data-params": "moderation_report[status]=handled" %>
+          <% end %>
+
+          <% menu.item do %>
+            <%= link_to "Reject", moderation_report_path(report.id), method: :put, remote: true, "data-params": "moderation_report[status]=rejected" %>
+          <% end %>
+        <% end %>
+      <% end %>
     <% end %>
 
     <%= numbered_paginator(@moderation_reports) %>

app/views/moderation_reports/update.js

@@ -0,0 +1 @@
+location.reload();