CompactBinnedArray maps bins in some coordinates to a vector of pointers
to objects.  It does not own this objects.

BinnedMaterial uses CompactBinnedArray, with the object in question
being a pair<> object.

When a BinnedMaterial is constructed, it takes a vector of pointers
to these pairs.  It does not take ownership of this pairs, but just
passes them to the CompactBinnedArray.

The callers of BinnedMaterial also do not take ownership of these pairs.
So they are presently leaked.

Further, BinnedMaterial can't just delete them, because these pairs
get shared between multiple BinnedMaterial instances.

We restructure like this.

BinnnedMaterial now gets a vector of pairs, which it saves as a member.
The CompactBinnedArray is then constructed to that it points at the
pairs in this vector.  BinnedMaterial now effectively owns the pairs.
These are now duplicated in each BinnedMaterial, but that should be ok.
We also need to extend CompactBinnedArray so that we can give it
a new vector of object pointers when it is cloned.

cf ATLASRECTS-5831.

CaloInterface, etc: Update tower builder tool interfaces.

See merge request atlas/athena!38956

Improve vertex finding / clustering in beamspot calibration.

Closes ATONLBS-30

See merge request atlas/athena!38957

Adding back the option doTrackSegmentsTRT to the FastChain test

See merge request atlas/athena!38932

Partial fulfilment of ATR-20700

See merge request atlas/athena!38903

Migrate TruthRivetTools to HepMC3

See merge request atlas/athena!38898

ATLASRECTS-5829: IApproachDescriptor use unique_ptrs for the remaining ptr data...

See merge request atlas/athena!38950

MuonIdentification: cmake and flake8 fixes

See merge request atlas/athena!38821

TrigSteeringEvent: Fix compilation with clang.

See merge request atlas/athena!38952

AthAllocators: Fix gcc11 warning.

See merge request atlas/athena!38946

TrkVertexFitterUtils+MuonCablingServers+TileTrackingGeometry: Fix clang warnings.

See merge request atlas/athena!38951

xAODRootAccess: Missing includes.

See merge request atlas/athena!38948

TrigOnlineMonitor: Add histograms to monitor number of forks, threads and slots

See merge request atlas/athena!38938

Add xAODDigest output to tests

See merge request atlas/athena!38936

BCM_RawDataByteStreamCnv: Fix placement of using declarations.

See merge request atlas/athena!38944

Met mon update dec2020

See merge request atlas/athena!38875

Add unit tests for the ByteStreamMetadataTool

See merge request atlas/athena!38959

Fix the tau FTF collections in the nightly tests, add a new tau test

See merge request atlas/athena!38891

Fix tau analyses for the tier 0 and physval monitoring

See merge request atlas/athena!38892

CaloTriggerTool: cmake fix

See merge request atlas/athena!38943

Add CostMonitoring.monitorROBs flag

See merge request atlas/athena!38874

Add Container name to object Refs kept in DataHeader_p6

See merge request atlas/athena!38886

TrackParticleCreator : EventContext aware .

See merge request atlas/athena!38887

Suppress further MDT calib warnings

See merge request atlas/athena!38912

AnalysisTop: Remove unneeded info from metadata

See merge request atlas/athena!38919

tau physval monitoring: merge TauHistUtils into TauDQA, and start cleanup

See merge request atlas/athena!38911

RootUtils: Remove kCharStar from the list of root types we handle.

See merge request atlas/athena!38905

Refactor code to read GeoDB

See merge request atlas/athena!38926

PyUtils: add Python package dependencies to `acmd cmake depends`

See merge request atlas/athena!38812

porting the ML-based HLT track seeding from 21.3 to master

See merge request atlas/athena!38838

fix for filling distributions for run3 TauTrigger monitoring

See merge request atlas/athena!38921

Migrate Muon Raw Data Decoding to use Region Selector Tool

See merge request atlas/athena!38922

Add flags for FastCaloMT

See merge request atlas/athena!38925

Rename id trackingcfg maker to have specific name

See merge request atlas/athena!38939

Small fix for python error when diff-ing root files

See merge request atlas/athena!38933

Add ITk dictionary file

See merge request atlas/athena!38934