This PR changes `nu_path::expand_path_with()` to no longer remove trailing slashes. It also fixes bugs in the current implementation due to ineffective tests (Fixes #12602).
# Description This PR adds a fuzzer for the nu-path and the nu-parser crate. Now you can go to `crates/nu-path/fuzz`/`crates/nu-parser/fuzz` and run `cargo fuzz` to find crashes. https://github.com/nushell/nushell/issues/10365 and #9417 was found by this --------- Co-authored-by: sholderbach <sholderbach@users.noreply.github.com>
