conf: credentialpath is not recalculated when it's a relpath

[Suor]

This one supposed to be relative to config file and converted to absolute and back on config load/save. This is done for cache.dir, local urls and gdrive_user_credentials_file, but not for credentialpath, which is used in s3 and gs.

Example: cache.dir - https://dvc.org/doc/command-reference/cache/dir#description.

[damakuno]

@efiop @Suor can I work on this issue? I'll probably need a bit more clarification as well

[godfryd]

@efiop I started looking into this.

[shcheklein]

@damakuno thanks 🙏 to clarify, we discussed this with @godfryd offline a while ago and he had agreed to take a look. Could you please find another ticket? Let me know if you need my help on this.

[damakuno]

@shcheklein alright, I'll look for another ticket then 👍