Have webdav directory listing utilize token-based authorization

[bbockelm]

We think, when stashcp does the directory existence test, it uses a library that doesn't leverage the bearer token. Investigate this issue and, as necessary, add token support.

Alternately, if token support isn't available, rip out this code.

[bbockelm]

@matyasselmeci points out this probably also breaks recursive transfers (which increases the priority to fix).

[turetske]

Client side code. Interface for listing remote directories. The token isn't being passed to the web-dev library or it's being passed. "list-directory" function. Possibly customize the http headers.

[turetske]

@bbockelm Looking into the code, gowebdav doesn't support this. However, there is an open issue for a fix on their repo, how do we feel about me attempting that rather than ripping out the code?

[bbockelm]

What's the GH issue you found? We should at least get that linked to this one.

[turetske]

What's the GH issue you found? We should at least get that linked to this one.

It's linked here: studio-b12/gowebdav#61

I did look into adding the support to the base web directory, but honestly my token/http knowledge still feels to weak to do so, so instead I'm removing the isDir code and we can fix it later.

[bbockelm]

I'm OK with fixing the directory listing / upload on a future ticket. Will merge the PR momentarily.