Error if layer or thematic is not found, or if an invalid param is provided
// returns the family of thematic id=3 of layer id=7
let family = JMap.Layer.Thematic.getFamilyTypeById(
layerId: 7,
thematicId: 3
)
console.log(family)
// "Classification"
JMap.Layer.Thematic.getFamilyTypeById
Returns the family of the specified layer thematic