Move stats graph partial to a component

Note we're naming it "chart" in order to avoid possible conflicts with
the "graph" view when we move it to a component.

app/components/admin/stats/chart_component.rb

@@ -0,0 +1,27 @@
+class Admin::Stats::ChartComponent < ApplicationComponent
+  attr_reader :name, :event, :count
+
+  def initialize(name:, event:, count:)
+    @name = name
+    @event = event
+    @count = count
+  end
+
+  private
+
+    def chart_tag(opt = {})
+      opt[:data] ||= {}
+      opt[:data][:graph] = admin_api_stats_path(chart_data(opt))
+      tag.div(**opt)
+    end
+
+    def chart_data(opt = {})
+      data = nil
+      if opt[:id].present?
+        data = { opt[:id] => true }
+      elsif opt[:event].present?
+        data = { event: opt[:event] }
+      end
+      data
+    end
+end