load-db-hpoa_by_pub should stream output

[cmungall]

currently this loader will only generate output at the end. the reason it does this is that it needs to aggregate by pub. however the strategy is still pretty dumb. And v inconvenient

curate-gpt/src/curate_gpt/wrappers/clinical/hpoa_wrapper.py

Lines 112 to 114 in 42fbc01

	if self.group_by_publication:
	for pub in by_pub.values():
	yield pub

instead it should

1. load all hpoa as one TSV
2. aggregate by pub
3. index these one at a time, yielding results

@julesjacobsen