fix(xcelium): handle xrun_options passed from FuseSoC command line

[tymonx]

Closes #530

This PR:

• Fixes passing the --xrun_options="<args>" from the fusesoc command line interface to the Edalize xcelium backend

Correct way to enable handling list for an option: olofk/fusesoc#791 (comment)

[olofk]

Hmm... it's a clever solution, but xrun_options should really be a list and I think we better fix that bug instead. I didn't catch that when I did the initial review.

[tymonx]

@olofk Alternatively we could introduce a new type list or args. But this is not supported on the FuseSoC side:

https://github.com/olofk/fusesoc/blob/f15e1c8a76815c4f391231dd0e743e2b683c6b45/fusesoc/edalizer.py#L335

    def _build_parser(self, backend_class, edam):
        typedict = {
            "bool": {"type": str2bool, "nargs": "?", "const": True},
            "file": {"type": str, "nargs": 1, "action": FileAction},
            "int": {"type": int, "nargs": 1},
            "str": {"type": str, "nargs": 1},
            "real": {"type": float, "nargs": 1},
        }

I can create an issue and PR in the FuseSoC project to add the list or args type and later update this PR.

The str type is definitely not clear here because core files are using YAML array with strings and tool backend is expecting list of arguments (aka list of strings).

[tymonx]

For now, I have moved this PR to the Draft state. I will create a separate PR in the FuseSoC project olofk/fusesoc#790 to add the list type and refactor this PR to use that type instead of the str type.

[tymonx]

If this will be merged olofk/fusesoc#791 then this PR can be simplified by replacing the str type with the list type.

[tymonx]

@olofk Ready for review and approve. Sorry for the mess with the list type. I followed your comment from the FuseSoC project: olofk/fusesoc#791 (comment)

I have added only the "list": True to the xrun_options.