Adding support for multi-level organization

[anandhu-eng]

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Migrated from mlcommons/mlperf-automations_archived#37
Originally created by @arjunsuresh on Fri, 31 Mar 2023 10:25:49 GMT

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Currently all the scripts are in one directory and this can be a problem while browsing (either locally or online) when the number of scripts grow. One possible solution would be to allow multi-level organization with the condition that in any file path from the root directory there can be at most one _cm.json file. This can be useful for other automations too where we can keep the related folders together.