Multi-Currency Part 2 (#543)

* Support all currencies, handle outside DB

* Remove currencies from seed

* Fix account balance namespace

* Set default currency on authentication

* Cache currency instances

* Implement multi-currency syncs with tests

* Series fallback, passing tests

* Fix conflicts

* Make value group concrete class that works with currency values

* Fix migration conflict

* Update tests to expect multi-currency results

* Update account list to use group method

* Namespace updates

* Fetch unknown exchange rates from API

* Fix date range bug

* Ensure demo data works without external API

* Enforce cascades only at DB level

config/initializers/constants.rb

@@ -1,7 +0,0 @@
-EXCHANGE_RATE_ENABLED = ENV["OPEN_EXCHANGE_APP_ID"].present?
-
-BALANCE_SHEET_CLASSIFICATIONS = {
-  asset: "asset",
-  liability: "liability",
-  equity: "equity"
-}.freeze

config/locales/views/account/en.yml

@@ -11,5 +11,7 @@ en:
         placeholder: Example account name
       select_accountable_type: What would you like to add?
       title: Add an account
+    sync:
+      success: Account sync started
     update:
       success: Account updated successfully

config/routes.rb

@@ -9,6 +9,7 @@ Rails.application.routes.draw do
 
   resources :transactions
   resources :accounts, shallow: true do
+    post :sync, on: :member
     resources :valuations
   end