obtain childless descendents of a term (including query)
Examples
ch = getOnto("chebi_lite")
#> loading from cache
alldr = getLeavesFromTerm("CHEBI:23888", ch)
head(ch$name[alldr[1:15]])
#> CHEBI:86327 CHEBI:35705 CHEBI:50847
#> "antifungal drug" "immunosuppressive agent" "immunological adjuvant"
#> CHEBI:88188 CHEBI:35481 CHEBI:35482
#> "drug allergen" "non-narcotic analgesic" "opioid analgesic"