fix: Fixed cache restoration for an entry with a very long name (#6662)
### Description
Fixes tar restoration for an entry that contains a really long name.
Turns out we need to call for the path via the entry and not the header,
since the header will give the raw, truncated name.
### Testing Instructions
We already had a test, I just fleshed it out to check that we restore
the correct name.
Closes TURBO-1818