Prepare for the rename of DataObjectHandleBase to DataHandle

This is a backward compatible change in preparation for gaudi/Gaudi!1091 (merged). Related to Moore!569 (merged).

added backport run2 label

/ci-test --merge

• [2020-07-11 09:51] Validation started with lhcb-master-mr#1071
• [2020-07-16 08:13] Validation started with lhcb-master-mr#1089
• [2020-07-23 11:59] Validation started with lhcb-master-mr#1105

assigned to @msaur

changed the description

mentioned in merge request Moore!569 (merged)

mentioned in issue Moore#198 (closed)

assigned to @abrearod and unassigned @msaur

approved this merge request

assigned to @jonrob

unassigned @jonrob

assigned to @jonrob and unassigned @abrearod

This was tested with Moore!569 (merged) @jonrob

added lhcb-head label

resolved all threads

merged

mentioned in commit 2bfe9514

unassigned @jonrob

mentioned in issue Moore#200 (closed)

mentioned in commit 3ca82563

added Configuration label

added modernisation label

mentioned in merge request !2676 (merged)

removed backport run2 label

run 2 "backport": !2676 (merged)

mentioned in commit 099840e7