Add basic tables and graphs for various tables.

Add basic tables and graphs for viewing things like uploads over time, new users
over time, comments over time, etc. Located at https://betabooru.donmai.us/reports.

The graphing uses Apache ECharts: https://echarts.apache.org/en/index.html.

app/logical/concerns/searchable.rb

@@ -744,16 +744,15 @@ module Searchable
   end
 
   def sql_value(value)
-    if Arel.arel_node?(value)
+    case value
+    in _ if Arel.arel_node?(value)
       value
-    elsif value.is_a?(String)
-      Arel::Nodes.build_quoted(value)
-    elsif value.is_a?(Symbol)
+    in Symbol
       arel_table[value]
-    elsif value.is_a?(Array)
+    in Array
       sql_array(value)
     else
-      raise ArgumentError
+      Arel::Nodes.build_quoted(value)
     end
   end