Option to add trailing slashes

[fleimgruber]

As a user, I want to add trailing slashes to requests. I found

webdav4/src/webdav4/client.py

Line 358 in 4c2046e

add_trailing_slash: bool = False,

but no way to set this kwarg.

Related #136 talks about follow_redirects but that did not work for me.

[skshetry]

Does a link without trailing slash redirect to a url with a slash? iirc if it does, it should work (I see we do follow_redirects=True on propfind).

We strip trailing slashes in many places, so that's what causes the problem in many places. Unfortunately, I don't have time anytime soon to work on this. PRs are welcome.
(We also need to look into WebDAV standard for compliance with what the link format should be (canonical or not, etc).