BaseSampleFormatter -- `_fill_row_core` does not support case of multiple sentences

[nicolay-r]

As we may extract attitudes between objects that are mentioned anywhere in text, we still limited by a single sentence due to the related method API, which includes sentence_ind parameter.

AREkit/arekit/common/experiment/input/formatters/sample.py

Lines 104 to 105 in 9b83f93

	def _fill_row_core(self, row, linked_wrap, index_in_linked, etalon_label,
	parsed_news, sentence_ind, s_ind, t_ind):

And we rely on the source position of the (source,target) pair EntityEndType.Source:

AREkit/arekit/common/experiment/input/formatters/sample.py

Lines 158 to 164 in 9b83f93

	self._fill_row_core(row=row,
	parsed_news=parsed_news,
	sentence_ind=TextOpinionHelper.extract_entity_position(
	parsed_news=parsed_news,
	text_opinion=text_opinion,
	end_type=EntityEndType.Source,
	position_type=TermPositionTypes.SentenceIndex),

[nicolay-r]

Solution here is to utilize a couple parameters [sentence_from, sentence_to]