refactor(turborepo): cli::run and args processing (#5297)
### Description
The `cli::run` function is pretty confusing and had a bug where
`--skip-infer` would accidentally pass a relative path to the Go code
and cause an error. I refactored this by moving all of the mutation to
the end of the function so we can validate the different code paths a
little easier. In the future we should do a scheme where `Args` is
parsed into a separate struct with all of the fields properly validated
and normalized.
This also moves `LogTag` so that if we encounter an error with
constructing a `CommandBase`, we error instead of segfaulting.
### Testing Instructions
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Co-authored-by: --global <Nicholas Yang>
