feat(vql): add reformat function

[nullifysecurity]

This change introduces a new reformat function that wraps the existing VQL reformatting logic, allowing artifact authors to call it directly from queries to reformat their artifacts.

It also updates the artifacts reformat command to align with Velociraptor’s general approach, keeping the CLI as a thin layer over the underlying VQL functionality.

Right now, the reformat function accepts the artifact content as a string, similar to how the verify function works. I’m wondering whether it would make more sense to switch this to a file argument instead and let the caller optionally provide an accessor. Would that be a better fit and provide more flexibility?

As always, let me know if there is anything you would like me to clarify or change! 😃