Move all BL to the manager. The ArgParser now only parses the CLI
arguments and creates a command which contains which command was run. In
turn, this information is passed to the manager, which will run the
appropriate business logic.
This will make it easier to add new options, separating the parsing of
the CLI options from the implementation of the logic. It also simplifies
any future effort in adding a different input (e.g. GUI).
Warning: some function were commented out, this is only a tracer bullet.
To improve the code organization, additional subfolders were added into
the pfbudget module.
The barebones of renewing the token and downloading transactions
directly from the banks through the Nordigen API were also added.
Issues #13, #15
