The WebDAV implementation already permits redirects on PROPFIND for
listing paths in the `listAll` method but does not permit this for
metadata in `readMetaDataForPath`. This results in a strange experience
for endpoints that heavily use redirects -
```
rclone lsl endpoint:
```
functions and lists `hello_world.txt` in its output but
```
rclone lsl endpoint:hello_world.txt
```
Fails with a HTTP 307.
The git history for this setting indicates this was done to avoid
an issue where redirects cause a verb change to GET in the Go HTTP
client; it does not appear to be problematic with HTTP 307.
To fix, a new `CheckRedirect` function is added in the `rest` library
to force the client to use the same verb across redirects, forcing this
for the PROPFIND case.
cf240b6c0f