Fix "No such file or directory (os error 2)"

[rumia-san]

Fixes #2

It seems that after the function call handle.await_complete();, the threads were exetuted and the folders has been already deleted.

However, the following lines https://github.com/XtremeDevX/turbo-delete/blob/0.0.1/src/main.rs#L108-L135 still tried to access the deleted folders and it reports IO error.

So I check whether the path exists before iterating the path again.

BTW, I have done some small code refactoring, extracted a new function : )

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Before Fix:

After fix:

[suptejas]

Great job on this PR, do you have benchmarks for before vs after this implementation for speed? We need to make sure it doesn't have a big speed impact :)

[rumia-san]

Great job on this PR, do you have benchmarks for before vs after this implementation for speed? We need to make sure it doesn't have a big speed impact :)

For my benchmarks, the speed with and without my code change were almost the same. So the speed impact should be small.

BTW, I used cargo build --release to build the binaries, but even I built your repo without any code changes, the exe is still bigger than your "td.exe". I'm confused.
So I didn't update the binaries under the "bin" folder since the binary built by me is a llitle bigger. Sorry for the incovinience...