* FIX holdings and exchange rate
- Fix holdings not showing total return instead showing day change %
- Fix exchange rate saving 0 for holidays, use LOCF - Last Observation Carried Forward
* Fix failing test
* feat: Add Twelve Data provider for exchange rates and securities
* test: fix hosting controller test, linting
* fix: add countries gem to handle country codes in Twelve Data provider
* fix: allow security search combobox to have no logo
* refactor: update Twelve Data provider use time series endpoint
* fix: set twelve data as default provider