[#62779116] added entity.accounts unit test
[#62779116] added mockjax framework, added mocks to unit tests, expanded EntityViewModel.accounts test
[#62779116] added AccountViewModel tests
[#62779116] changed all id properties to observable, added isValid obserable to ServiceEntity, added validation to entity view model, added unit tests
[#62779116] added includedIn validation extension and applied it to account type
removed immediate save request on amount and account_id change in transaction item view model
[#62779116] added transaction view model unit tests, moved formattedTransactionDate implementation from transaction item view model to transaction view model
[#62779116] added equalTo validating extender and applied it to transactino view model credit and debit amounts. added errorMessages method to service entity
[#62779116] added unit tests for TransactionViewModel.creditAmount and debitAmount