Assert on abs path to path constructor with frame
Assert on abs path to path constructor with frame

Found a case where users could pass Path("/a/b/c", Path("/1/2/3"))
resulting in "/1/2/3/a/b/c" but would have expected "/a/b/c".

Added assert to catch the case for further analysis.

andrewguy9/farmfs,andrewguy9/farmfs