Add breakdown of usage by source to admin UI for hashtags (#11517)

Allows determining where the majority of posts in a hashtag come
from on a given day at a glance.

app/views/admin/tags/show.html.haml

@@ -1,6 +1,22 @@
 - content_for :page_title do
   = "##{@tag.name}"
 
+.dashboard__counters
+  %div
+    = link_to web_url("timelines/tag/#{@tag.name}") do
+      .dashboard__counters__num= number_with_delimiter @accounts_today
+      .dashboard__counters__label= t 'admin.tags.accounts_today'
+  %div
+    %div
+      .dashboard__counters__num= number_with_delimiter @accounts_week
+      .dashboard__counters__label= t 'admin.tags.accounts_week'
+  %div
+    = link_to explore_hashtag_path(@tag) do
+      .dashboard__counters__num= number_with_delimiter @tag.accounts_count
+      .dashboard__counters__label= t 'admin.tags.directory'
+
+%hr.spacer/
+
 = simple_form_for @tag, url: admin_tag_path(@tag.id) do |f|
   = render 'shared/error_messages', object: @tag
 
@@ -14,3 +30,16 @@
 
   .actions
     = f.button :button, t('generic.save_changes'), type: :submit
+
+%hr.spacer/
+
+%h3= t 'admin.tags.breakdown'
+
+.table-wrapper
+  %table.table
+    %tbody
+      - @usage_by_domain.each do |(domain, count)|
+        %tr
+          %th= domain || site_hostname
+          %td= "#{number_with_delimiter((count.to_f / @tag.history[0][:uses].to_f) * 100)}%"
+          %td= number_with_delimiter count