Transaction transfers, payments, and matching (#883)

* Add transfer model and clean up family snapshot fixtures

* Ignore transfers in income and expense snapshots

* Add transfer validations

* Implement basic transfer matching UI

* Fix merge conflicts

* Add missing translations

* Tweak selection states for transfer types

* Add missing i18n translation

db/migrate/20240614120946_create_transfers.rb

@@ -0,0 +1,7 @@
+class CreateTransfers < ActiveRecord::Migration[7.2]
+  def change
+    create_table :transfers, id: :uuid do |t|
+      t.timestamps
+    end
+  end
+end