1504 introduce migrations log file

[SandPod]

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Pre-launch Checklist

• I read the Contribute page and followed the process outlined there for submitting PRs.
• This update contains only one single feature or bug fix and nothing else. (If you are submitting multiple fixes, please make multiple PRs.)
• I read and followed the Dart Style Guide and formatted the code with dart format.
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• I added new tests to check the change I am making.
• All existing and new tests are passing.
• Any breaking changes are documented below.

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Breaking changes

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