Create a service that manages entities via redux that abstracts the redux logic

[msivri]

Need to create a service that can be inherited by other services to manage entities via redux, mainly ngrx. The definitions are as the following:

• Entity: Typescript class objects that are are passed around the client and the web API. Usually a view model. Can also manage foreign relationships.
• Entity Service: A service with the generic type Entity that manages CRUD for the entity.
• Entity Actions: Handles dispatching actions for the Entity Service.
• Entity Reducer: Handles transformations to the Entity.
• Entity Effects: Processes actions that are dispatched and parses results.
• Entity Mapper: Maps API response to the correct entities and dispatches actions to perform CRUD operations to the relating entities.
• Entity Data Service: Performs API operations that include GET, ADD, UPDATE, DELETE and uses fluent API to build requests.

Also need helper decorators and pipes:

• @EntityFK: Used by entity properties to identity foreign keys that relate to another entity. Helps filtering in the UI via pipes.
• FilterEntityByFK and FirstEntityByFK Pipe: Used by the UI to filter observable entities by their FK given the foreign entity type. Useful for nested observables.

Main dependencies:

• Angular
• NGRX: simplifies redux
• classTransformer: Converts plain javascript objects to entity classes.