Create shared ruler and standardize across views (#2240)

* Create shared ruler view

* Use collection rendering/spacer templates for rules, and new shared_ruler

* Use shared ruler for all the places a ruler is used

* Use shared ruler for imports and balance sheet

* Fix brakeman by using a static partial with a defined collection

* Update balance sheet

app/views/valuations/index.html.erb

@@ -27,7 +27,7 @@
           <%= render partial: "valuations/valuation",
                      collection:      @entries,
                      as:              :entry,
-                     spacer_template: "entries/ruler" %>
+                     spacer_template: "shared/ruler" %>
         <% else %>
           <p class="text-secondary text-sm p-4"><%= t(".no_valuations") %></p>
         <% end %>