`OSPSuite.R.Services.DataImporterTask.ImportExcelFromConfiguration` should throw an error when specified sheets are not found

[PavelBal]

When trying to load data from a sheet that does not exist in the excel file, the importer just silently returns nothing. Instead, an error should be thrown.

configurationPath <- getTestDataFilePath(
  "dataImporterConfiguration_noSheets.xml"
)
xlsFilePath <- getTestDataFilePath("CompiledDataSet_oneSheet.xlsx")
importerConfiguration <- loadDataImporterConfiguration(configurationPath)

importerConfiguration$sheets <- "blubb"

dataSets <- loadDataSetsFromExcel(
    xlsFilePath = xlsFilePath,
    importerConfigurationOrPath = importerConfiguration,
    sheets = NULL
  )

> dataSets
named list()