Removal of Microsoft ADAL identity and to use azidentity(MSAL)

[aagusuab]

Currently, usage of ADAL for Azure's credentials/identity is being deprecated, we should use MSAL instead. This PR erases the old code that uses the ADAL.

Checklist

• When introducing a new scaler, I agree with the scaling governance policy
• I have verified that my change is according to the deprecations & breaking changes policy
• Tests have been added
• Changelog has been updated and is aligned with our changelog requirements
• A PR is opened to update our Helm chart (repo) (if applicable, ie. when deployment manifests are modified)
• A PR is opened to update the documentation on (repo) (if applicable)
• Commits are signed with Developer Certificate of Origin (DCO - learn more)

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