refactor(turbo-tasks): Make TraceRawVcs a supertrait of TaskInput (#77397)
For a tracing GC to work (different for cache eviction), we need `TraceRawVcs` to be able to inspect function arguments.
While a tracing GC is still far off, the immediate motivation here is using tracing to improve logging for "transient task called from persistent task" error messages.
There's one non-test mpsc queue (`ComputeUpdateStreamSender`) with a sketchy `TraceRawVcs` impl. We should have a way of excluding certain objects from GC (marking them as roots) to fix this in the GC case. IMO this doesn't really matter for non-GC debug use-cases of `TraceRawVcs`.