[C++] FilesystemFromUriOrPath and FileSystemFromUri should always remove trailing slash

[westonpace]

Describe the enhancement requested

This is a fairly minor change but it is something I encountered trying to simplify the implementation of these methods in #34420. Currently, these methods may or may not remove the trailing slash from a path. For example:

FileSystemFromUriOrPath("s3://foo/bar/", &out_path);
FileSystemFromUriOrPath("file:///foo/bar/", &out_path);

The former returns foo/bar and the latter returns /foo/bar/. I think the change leading slash being different between the two is ok. However, I think there is no reason to remove the trailing slash in one instance and not the other.

No work needs to be done here, I'm addressing this already in #34420 . However, I wanted to open a new issue to ensure visibility in case someone was relying on the old behavior or knew of a reason that the old behavior existed.

Component(s)

C++

[wjones127]

Not sure why that was the old behavior, but I remember there were inconsistencies with trailing slashes elsewhere in the API that I fixed in #13577.

[westonpace]

I'm going to close this then. #13577 is helpful. Since the filesystems will reject the trailing slash anyways it seems good that PathFromUriOrPath shouldn't generate them.

I suppose it could be argued that PathFromUriOrPath should reject a trailing slash to match the filesystems API. However, since things have merged, let's say if someone wants to make that change they can reopen.