translation: Update chapter_computational_complexity/performance_evaluation.md

[ymmmas]

I've added some parts to align with the Chinese version and rephrased certain sentences for better readability. I personally prefer the term 'Practical Testing' over 'Actual Testing' because it is more commonly used and more relevant to the content. However, I'm not certain about the definitive correct term, so didn’t make the change.

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[SamJin98]

minor changes :)

[yuelinxin]

Great work, please consider my comment