duplicate functions for flow mapping

[bl-young]

SInce v2.0, there are two functions that handle flow mapping and they are not used consistently:

flowsa/flowsa/sectormapping.py

Lines 75 to 91 in e7d35a1

	def map_flows(fba, from_fba_source, flow_type='ELEMENTARY_FLOW',
	ignore_source_name=False, **kwargs):
	"""
	Applies mapping via esupy from fedelemflowlist or material
	flow list to convert flows to standardized list of flows
	:param fba: df flow-by-activity or flow-by-sector
	:param from_fba_source: str Source name of fba list to look for mappings
	:param flow_type: str either 'ELEMENTARY_FLOW', 'TECHNOSPHERE_FLOW',
	or 'WASTE_FLOW'
	:param ignore_source_name: bool, passed to apply_flow_mapping
	:param kwargs: optional - keep_unmapped_rows: False if want
	unmapped rows dropped, True if want to retain and keep_fba_columns:
	boolean, True or False, indicate if want to maintain
	'FlowName' and 'Compartment' columns in returned df
	:return: df, with flows mapped using federal elementary flow list or
	material flow list
	"""

flowsa/flowsa/flowbyactivity.py

Lines 130 to 135 in e7d35a1

	# TODO: probably only slight modification is needed to allow for material
	# flow list mapping using this function as well.
	def map_to_fedefl_list(
	self: 'FlowByActivity',
	drop_unmapped_rows: bool = False
	) -> 'FlowByActivity':

I don't believe this is causing any errors but the duplication is confusing