Multiple unescaped trailing path separators should be trimmed from input elements so there are no empty elements or trailing unescaped separators at the end of the path or between elements
* Rewrite basic path logic to be simpler
Make basic path logic deal only with path elements instead of elements
and segments. Upper-layer logic can deal with elements.
Base path logic does not require a complete resource path as would be
seen by kopia, it just manages splitting/joining/escaping path elements.
Will have transformers to go from a basic path to a resource specific
path in a follow up.
Remove upper-layer logic for now to reduce load while reviewing as it
also changed slightly. Will be re-added in a follow up
* Function and tests for returned unescaped elements
* Regression test and fix for empty segment bug
If a raw segment had no elements that had length > 0 or just didn't have
any elements it would still create a segment, throwing everything else
off. Explicitly test for that now.
