Refactor log parser#24

Hide the implementation details from the armada router and enable better organized tests. This ended up being a much bigger changeset than I anticipated because this refactor found a bug in the parsing logic where if one of the CSVs had an empty data set (e.g. the combat was a defeat so we gained no loot/rewards) the schema was not detected properly. So now we do some special handling to first detect the schema, then we parse the file with the correct parser, keeping track of the type of the data even if it's empty.