fix warnings for REMIND inputdata generation

[fbenke-pik]

changes

• set where argument when calling toolGetMapping
• set warnNA = FALSE when calling calcOutput
• suppress warnings when converting data frame columns to numeric (NAs introduced)
• set verbosity to lowest when calling toolCountryFill
• explicitly set no_remove_warning to affected countries when calling toolCountryFill
• replace getRegions<-by getItems<-
• remove renaming messages when reading in excel files by setting .name_repair = "unique_quiet"
• remove getConfig("sourcefolder") from some madrat functions
• remove hardcoded warnings and notes that spam up the log
• removes some variables and functions that are never used and some commented code

validation on the cluster

madrat::compareData("/p/projects/rd3mod/inputdata/output/rev6.75falk-before_2b1450bc_remind.tgz",
                    "/p/projects/rd3mod/inputdata/output/rev6.75falk-compare_2b1450bc_remind.tgz")

madrat::compareData("/p/projects/rd3mod/inputdata/output/rev6.75falk-before_62eff8f7_remind.tgz",
                    "/p/projects/rd3mod/inputdata/output/rev6.75falk-compare_62eff8f7_remind.tgz")

[dklein-pik]

101 files, unbelievable. Thanks for fixing!