Refactor diffs module to use ModelDiffRunner class

[SujataSaurabh]

[github-actions[bot]]

MLCommons CLA bot:
Thank you very much for your submission, we really appreciate it. Before we can accept your contribution, we ask that you sign the MLCommons CLA (Apache 2). Please use this [Google form] (https://forms.gle/Ew1KkBVpyeJDuRw67) to initiate authorization. If you are from an MLCommons member organization, we will request that you be added to the CLA. If you are not from a member organization, we will email you a CLA to sign. For any questions, please contact [email protected].
0 out of 1 committers have signed the MLCommons CLA.
:x: @Sujata Goswami
Sujata Goswami seems not to be a GitHub user. You need a GitHub account after you become MLCommons member. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You can retrigger this bot by commenting recheck in this Pull Request}

[priyakasimbeg]

@SujataSaurabh could you sign the CLA form again with your email you use for github? The CLA check on this PR is failing. The form can be found here: https://forms.gle/Ew1KkBVpyeJDuRw67.

[priyakasimbeg]

This looks like a good start! Could you modify the compare.py files to use the ModelDiffRunner as well in this PR?