Refactor ArchesFileReader.import_business_data() for readability

[jacobtylerwalls]

At its maximum, there are 21 levels of indentation in this function. We should refactor to avoid so much indentation.

(The github preview below doesn't do it justice, so click through):

arches/arches/app/utils/data_management/resources/formats/archesfile.py

Lines 460 to 466 in c6b043a

	if (
	child_tile_cardinality
	== "1"
	):
	populated_child_nodegroups.append(
	prototype_tile.nodegroup_id
	)

[caineblood]

The above comment asking you to download a file is malware to steal your account; do not under any circumstances download or run it. The post needs to be removed. If you have attempted to run it please have your system cleaned and your account secured immediately.

[chiatt]

It would be nice to transition away from this and the csvfile importer and use the bulk data manager for these formats instead.