tests: Fix bugs related to gem5 Vision

This patch fixes refs under tests/pyunit/stdlib/resources.

Removes instances of {url_base} in refs.

Also, renames two refs: mongo_mock and mongo_dup_mock
to mongo-mock and mongo-dup-mock to follow naming
convention of other refs.

Change-Id: If115114bc7a89764e7c546b77a93d36d6a3b5f8a
Co-authored-by: Parth Shah <helloparthshah@gmail.com>
Co-authored-by: Harshil2107 <harshilp2107@gmail.com>
Co-authored-by: aarsli <arsli@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/71378
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
5 files changed