De multi thread

[jenyav94]

Summary

This PR aims to introduce the batch fitness evaluation scheme to enhance the de algorithm.

Overview

• This PR preserves the previous functionality as a fallback when bfe is not initialized.
• When bfe is initialized, all mutations are calculated prior to fitness function evaluation, which is then performed in a batch.
• The PR separates mutation and population update into distinct functions for improved code organization.

[bluescarni]

@jenyav94 thanks for the PR and sorry for the delay in replying.

I have asked @darioizzo to take a look as he is the author of the original algorithm, but he won't be able to spend time on this until the end of the month or so.