Simplify JavaScript to toggle investment selection

We don't need to replace the whole row, since the changes only affect
the button. Therefore, we don't need to depend on an `inserted` event to
decide which columns to render in that row.

app/views/admin/budget_investments/toggle_selection.js.erb

@@ -1,3 +1,3 @@
-$("#<%= dom_id(@investment) %>").replaceWith(
-  "<%= j render Admin::BudgetInvestments::RowComponent.new(@investment) %>"
-).trigger("inserted");
+$("#<%= dom_id(@investment) %> [data-field='selected']").html(
+  "<%= j render(Admin::BudgetInvestments::ToggleSelectionComponent.new(@investment)) %>"
+);