#refactoring declarative error handling

[germanf]

Changes

• refactoring declarative global error handling with ErrorBoundary Component

• removed imperative error handling from sagas, reducers, actions, constants & test files
• added onError handler to sagaMiddleware, it's in charge of catch errors in saga cycles and propagation of them to ErrorBoundary
• global catch error for request & client side errors
• wrap & throwing of API error responses to JS Error
• added app root directory to WebPack aliases to automatic resolve file paths in root
• clean code