CbmEvent: Number of objects returns 0 now for empty branches

In its current implementation, CbmEvent::GetNofData(ECbmDataType) returns -1 if no data of this type are contained. This is changed to return 0 as expected. The return type is changed to size_t.

changed milestone to %OCT23

added Framework label

requested review from @se.gorbunov

assigned to @f.uhlig

Dear @f.uhlig, @v.friese, @p.-a.loizeau, @se.gorbunov, @v.akishina, @s.lebedev, @a.bercuci, @p.kaehler, @d.smith,

you have been identified as code owner of at least one file which was changed with this merge request.

Please check the changes and approve them or request changes.

added CodeOwners label

mentioned in merge request !1281 (closed)

approved this merge request

approved this merge request

added 6 commits

• 463535e2...8941a853 - 4 commits from branch computing:master
• e53ef44a - Change CbmEvent such as to return 0 for number of objects if no object exists (was -1 previously)
• e0761fcb - Correct documentation

Compare with previous version

enabled an automatic merge when the pipeline for e0761fcb succeeds

merged