Account:: namespace simplifications and cleanup (#2110)

* Flatten Holding model

* Flatten balance model

* Entries domain renames

* Fix valuations reference

* Fix trades stream

* Fix brakeman warnings

* Fix tests

* Replace existing entryable type references in DB

app/controllers/transactions/bulk_updates_controller.rb

@@ -0,0 +1,19 @@
+class Transactions::BulkUpdatesController < ApplicationController
+  def new
+  end
+
+  def create
+    updated = Current.family
+                     .entries
+                     .where(id: bulk_update_params[:entry_ids])
+                     .bulk_update!(bulk_update_params)
+
+    redirect_back_or_to transactions_path, notice: "#{updated} transactions updated"
+  end
+
+  private
+    def bulk_update_params
+      params.require(:bulk_update)
+            .permit(:date, :notes, :category_id, :merchant_id, entry_ids: [], tag_ids: [])
+    end
+end