Add TFlops calculator and stuck job monitor

[emeraldbay]

Issue #, if available:

Description of changes:

1/. Add training job TFlops calculator

2/. Add stuck job monitor, customer can monitor specific Cloudwatch log stream output specified. If customer did not see the expected output in Cloudwatch log stream for a while, we know the training job is stuck and act accordingly.

Testing done:

Merge Checklist

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