Retrieve default base dir off instance for default fs io manager
is the root instance storage directory right here? Looking at  are we worried at all about conflicts between different pipelines/jobs or anything?
Maybe at least put it in a "versioned_outputs" or "versioned" folder inside of "storage"
I just think it would be a bit odd to have all the run_id directories (which is what everything else writing to "storage" does I believe) then also all these solid name directories at the same level.
nit: this feels like a touch over specific. I doubt it would break since its going to be hard to change these paths, but the exact directory feels less important than that its in the instance directory
not directly related to this diff: shall we rename this to versioned_fs_io_manager to pair with fs_io_manager?
+1 to adding an extra layer like "versioned_outputs"/"versioned"
should we just call instance.storage_directory() instead of constructing the path here?