Preserve input column order for .janno and .ssf files?

[nevrome]

The reordering of columns is no technical necessity:

poseidon-hs/src/Poseidon/Janno.hs

Lines 402 to 409 in d4fe316

	makeHeaderWithAdditionalColumns :: [JannoRow] -> Csv.Header
	makeHeaderWithAdditionalColumns rows =
	V.fromList $ jannoHeader ++ sort (HM.keys (HM.unions (map (getCsvNR . jAdditionalColumns) rows)))
	writeJannoFile :: FilePath -> JannoRows -> IO ()
	writeJannoFile path (JannoRows rows) = do
	let jannoAsBytestring = Csv.encodeByNameWith encodingOptions (makeHeaderWithAdditionalColumns rows) rows
	Bch.writeFile path jannoAsBytestring

We could store the input column order and use it when writing. For forge we would need some sort of associative operation to combine the column orders of different packages.

This is not urgent. But I still think it is worth a look. Would prevent situations such as in #339.