Multi-currency support: Money + Currency class improvements (#553)

* Money improvements

* Replace all old money usage

app/views/shared/_trend_change.html.erb

@@ -4,7 +4,7 @@
   <% if trend.direction == "flat" %>
     <span>No change</span>
   <% else %>
-    <span><%= styles[:symbol] %><%= format_currency(trend.amount.abs) %></span>
+    <span><%= styles[:symbol] %><%= format_money trend.amount.abs %></span>
     <span>(<%= lucide_icon(styles[:icon], class: "w-4 h-4 align-text-bottom inline") %><%= trend.percent %>%)</span>
   <% end %>
 </p>