fix: Fix the parameter name of the first and last methods

[marien-probesys]

This PR fixes the documentation of the Persistent*ObjectFactory first() and last() methods.

I discovered the issue when calling MyFactory::first(sortedField: 'field') with the error:

Error: Unknown named parameter $sortedField

Indeed, the parameter is now named sortBy.

Then I realized that the field needed to be renamed also in the MakeFactoryPHPDocMethod class.

Finally, I also fixed the parameter name in the *RepositoryDecorator::last() method to be more coherent (the name was correct in the first() method).

[nikophil]

nice! thank you @marien-probesys