test-runner: support arbitrary test path for remote execution

[chase-qi]

Remote exec only support tests from automated folder, the structure of 'automated' is known, with this limitation, we are able to do partially file copy to target to reduce disk space occupation.

If it is needed in the future, or the disk space isn't a problem any more, we can also copy the whole repo for remote exec to allow arbitrary path and support 3rd party repo.