[BUG] ChargeState is incorrect

[jameswallacew8]

'GetChargeState' in 'MzIO.Thermo/ThermoRawFileReader.fs' does not return the ChargeState as it is accessing the incorrect index from the trailer data. This can be fixed by accessing index 7 instead:

static member private GetChargeState(rawFile:IRawDataPlus, scanNo:int) =
        // 7 is the index for charge state
        let trailerData = rawFile.GetTrailerExtraInformation(scanNo)
        Convert.ToInt32(trailerData.Values[7])