Allow direct orderbook export from degiro paexport to portfolio load command

[montezdesousa]

Description

This PR will allow users to export their orderbook from degiro #2065 directly into portfolio/holdings default paexport_degiro.csv file. Then the user can immediately load his orderbook through portfolio load command choices prompt.

To allow loading from path with load portfolio\holdings\[not_default_file_name].csv.r I removed choices=self.DATA_HOLDINGS_FILES, on the parser argument --file. This fixes part of #2101 by allowing users to load files from arbitrary paths as well.

        parser.add_argument(
            "-f",
            "--file",
            type=str,
            choices=self.DATA_HOLDINGS_FILES,
            dest="file",
            required="-h" not in other_args,
            help="The file to be loaded",
        )

• Summary of the change / bug fix.
• Link # issue, if applicable.
• Relevant motivation and context.

How has this been tested?

Fetch degiro transactions to csv through degiro paexport command
portfolio/bro/degiro/login
paexport -s 2018-01-01

Load previous file through portfolio load command
portfolio/load 20220719_224755_paexport_degiro.csv

Others

• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• My code passes all the checks pylint, flake8, black, ... To speed up development you should run pre-commit install.
• New and existing unit tests pass locally with my changes. You can test this locally using pytest tests/....

[Chavithra]

Working great on my side !