ColumnsProvider -- make provider accessable for columns editing [Gutenberg collection processing backlog]

[nicolay-r]

Problem: It is not possible to modify columns outside the sampler. Let's say we would like to display sent_ind which is calculated during sampling, but not listed in the related ColumnsProvider by being a task-specific requirement

How to fix this: There is a need to bring the related initialization of the provider to the upper level:

AREkit/arekit/contrib/utils/serializer.py

Lines 23 to 30 in 2bc0465

	def create_samples_repo(keep_labels, rows_provider, storage):
	assert(isinstance(rows_provider, BaseRowProvider))
	assert(isinstance(keep_labels, bool))
	assert(isinstance(storage, BaseRowsStorage))
	return BaseInputSamplesRepository(
	columns_provider=SampleColumnsProvider(store_labels=keep_labels),
	rows_provider=rows_provider,
	storage=storage)

Tricky moment is to consider other dependencies, based on the presence of the label column depending on the DataType. I do beleive it might be restructured, so BertExperimentInputSerializerPipelineItem or others might have access to the ColumnsProvider