Allow the user to specify the used driver

[xFrednet]

The driver for marker, is usually installed using the cargo marker setup command. This command installs the driver version hardcoded in cargo-marker. It would be good if the user could manually specify the driver version and toolchain.

Note, that the version and toolchain always have to be provided as a pair. It would be cool if marker would have a mapping of toolchain -> driver version. But the only way I can think of would require manually having a list. Having the user specify both for now, should be fine.

I believe the best solution for this, would be to add a new field to marker's configuration under the workspace.metadata.marker section in Cargo.toml

[workspace.metadata.marker]
driver = { version = "0.1.0", toolchain = "2023-07-13"}

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Optional: For testing purposes, it would also be cool if a path could be used instead of the version field. (Maybe guarded by the dev-build feature)