The Manager doesn't need to know that it was called from the CLI, so it
now is initialized with the database and performs an action, based on
the operation it receives and its parameters.
The work isn't finished, some Manager actions are still based on the CLI
arguments.
The CLI logic and creation of parameters to pass to the manager have
been moved to the __main__.py file, which brings it to line to the
program being called as a package from the command line.
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
