more robust flatten on joining project lists

[tsmathis]

^title

from:

MPContribs/mpcontribs-client/mpcontribs/client/__init__.py

Lines 1183 to 1185 in 304c934

	ret["data"].extend([resp["result"]["data"] for resp in responses.values()])
	return ret["data"]

to:

MPContribs/mpcontribs-client/mpcontribs/client/__init__.py

Lines 1183 to 1190 in c4a8983

	return list(
	itertools.chain.from_iterable(
	[
	ret["data"],
	[resp["result"]["data"] for resp in responses.values()][0],
	]
	)
	)

open question on safeness of the explicit index into the response list for users running the client

[esoteric-ephemera]

@tsmathis made some changes here for hopefully safer key access - should just return no data if those keys aren't there

also tried to prevent the client from modifying queries in place, since this was a barrier to us testing what was going wrong

[tsmathis]

nice, will test!