refactor: modifying _update_from_checkpoint signature

[jeandut]

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Summary

Notes

This PR introduces a change in the signature of the algorithm's update_from_checkpoint function in order to ease its use in complex pipelines. As of before this PR if you had a checkpoint (a dict from say a call to get_state_to_save) it was impossible to load it ... Now workflows can use patterns like:

chkpt = self.get_state_to_save()
self._update_from_checkpoint(chkpt)

Please check if the PR fulfills these requirements

• [x] If the feature has an impact on the user experience, the changelog has been updated
• [x] Tests for the changes have been added (for bug fixes / features)
• [x] Docs have been added / updated (for bug fixes / features)
• [x] The commit message follows the conventional commit specification

[jeandut]

Okay will copy checkpoint in the function however striving for functional purity is a bit of an unattainable ideal.