Fix dependence on Illumina (only) file name format to determine sample name

[AmandaBirmingham]

AFAIK, this method (metapool.merge_read_counts()) is only being used in the metagenomics, metatranscriptomics, and tellseq notebooks (plus unit tests), and these notebooks are only for use with Illumina sequencing. Still, we should really centralize this logic that digs sample names out of file names rather than implementing it independently in multiple parts of the codebase.

kl-metapool/metapool/metapool.py

Lines 1537 to 1542 in 6ebb094

	# Parse table to find sample names, and sum forward and rev reads.
	for i in counts_df.index:
	filename = counts_df.loc[i, sample_column]
	match = re.match(r'^(.*)_S\d+_L00\d', filename)
	if not match:
	raise LookupError(f'id not found in {filename}')