DataObjID: Add accessor for class name

Add accessor for the class name of DataObjID (for the ATLAS case). This avoids having to parse the result of fullKey().

cc @leggett

mentioned in merge request atlas/athena!36864 (closed)

changed milestone to %v34r1

added lhcb-gaudi-head label

assigned to @clemenci

• [2020-10-07 00:17] Validation started with lhcb-gaudi-head#2739

approved this merge request

merged

mentioned in commit aabbe5b3