Add check for duplicated obj names

[CeresBarros]

Just hit an interesting error that took me a while to debug.

I accidentally duplicated an object in the objects list which caused the end of simInit to crash (righ after completing the final inputObjects
The error was:

Oct29 15:43:15 simInit: frSns_ Running .inputObjects for fireSense_IgnitionPredict
Error in list2env(value, envir = [email protected]) : 
  attempt to use zero-length variable name

By inserting a browser at the end of the last inputObjects I was able to notice the "empty" slot in [email protected]$.userSuppliedObjNames.

Browse[1]> list2env([email protected])
Error in list2env([email protected]) : first argument must be a named list
Browse[1]> [email protected]$.userSuppliedObjNames
 [1] "studyArea"           "studyAreaLarge"      "sppEquiv"            "sppColorVect"        "speciesParams"      
 [6] "ecoregionLayer"      "PSPgis"              "PSPmeasure"          "PSPplot"             "rstLCC"             
[11] ""                    "fireLocations"       "nonForestFuelsTable" "FirePFGs2Fuels"      "weatherDataMDC"     
[16] "weatherData"         "weatherDataPred"     "weatherDataCRS"      "weatherDataMDCCRS"  

I was lucky that I checked that object first, I guess, because that made me realize that I had two "fireLocation" objects being passed and after removing one, the empty slot and error went away.
A good old "edge case", but perhaps a check for duplicated object names would prevent this "mysterious" error, which will be hard to debug for most people (or developpers without a good reprex) .