Verify that the System supports link with a tempfile before add

[skshetry]

Currently, we test if the system supports given link by trying to add the first output and then if it worked, we call it verified. But, it'd be better if we tried with a temporary file to see if it's really supported and then only, try to add outputs to the cache.

From #3428 (comment)
Issue: #3390

[skshetry]

Closing, as the mentioned way does not work for all kinds of links.