Copy the recording from original sorting during NumpySorting.from_sorting()

[ecobost]

When calling out_sorting = NumpySorting.from_sorting(sorting), out_sorting will also inherit the recording of the source.

This partly solves #4410 for the case when the analyzer is created in memory.

import spikeinterface.core.sortinganalyzer as sa

print(sorting.has_recording()) # True
analyzer = sa.create_sorting_analyzer(sorting, recording=sorting._recording)
print(analyzer.sorting.has_recording()) # True :)

print(sorting.has_recording()) # True
analyzer = sa.create_sorting_analyzer(sorting, recording=sorting._recording, format='binary_folder', folder='test_analyzer')
print(analyzer.sorting.has_recording()) # False :(