All methods' metadata['unit'] are 'Unknown' when importing Ecoinvent with ecoinvent_interface and using namespaced methods

[tngTUDOR]

Current

When importing ecoinvent using ecoinvent_interface all the units in the methods end up being "Unknown".

Expected

the metadata item 'unit' for the methods are set to the values from the xlsx LCIA Implementation spreadsheet.

[tngTUDOR]

When the key is recovered at:

brightway2-io/bw2io/ecoinvent.py

Line 383 in 79c3fbe

unit=units_mapping.get(key, "Unknown"),

it's probably not found when namespaced methods are used.

the units_mapping is built earlier with:

brightway2-io/bw2io/ecoinvent.py

Lines 297 to 300 in 79c3fbe

	units_mapping = {
	(row["method"], row["category"], row["indicator"]): row[units_col_label]
	for row in units
	}

but when using namespaced methods, the key of the units_mapping is missing the namespace