Reformat callback

[HDThang]

Background

• As discussed in the last PR, I removed the callback in each training script and placed it in a new module to be imported.

What does this PR do?

-Created a utility module for callback to be imported in each training script
-Moved duplicate code to utils/utils.py
-Reformatted all the training scripts to use the utility module

[loctxmoreh]

LGTM

Please make sure testbench are still able to launch these script (importing still work) before merging

[HDThang]

Please make sure testbench are still able to launch these script (importing still work) before merging
Then I'll need to do some testing before merging this PR.