* Placeholder logic for missing prices
* Generate holdings properly for "offline" securities
* Separate forward and reverse calculators for holdings and balances
* Remove unnecessary currency conversion during sync
* Clearer sync process
* Move price caching logic to dedicated model
* Base holding calculator
* Base calculator for balances
* Finish balance calculators
* Better naming
* Logs cleanup
* Remove stale data type
* Remove stale test
* Fix price lookup logic for holdings sync
* Fix Plaid item sync regression
* Remove temp logging
* Calculate cash and holdings series
* Add holdings, cash, and balance series dropdown for investments
