perform some renaming of locations and revert back changes to get closer to master and be better backward compatible

- moved 'populate' code to Rec
- further optimized packing by not storing fields that can be recomputed
- adapted the unbiased code to use 'velosegmentids' derived from LHCbIDs

removed old PrimaryVertex class and replaced by simple new one

- use this as a base class of ExtendedPrimaryVertex, the class stored by
  PrimaryVertexContainer
- introduce old--style packers/unpackers for PrimaryVertex
- added constexpr to propertyName of old-style packers
- added packing_mapping for soatype packers

- add pv unpacking to simple output check

- add routine to return single refitted unbiased vertex

PrimaryVertexContainer
- added unit test for PrimaryVertices

- streamlined PV unbiasing code
- updated Particle packing checker

add properties needed for packing  to PrimaryVertices
added PrimaryVertices to selective packer/unpacker

and make `unpack` return a StatusCode to know when an unpacker has
failed, in which case, if available, another unpacker for the same
CLID can be tried

SIMD ML inference backend

See merge request !4305

Add option to ANNSvc to publish decoding keys to monitoring hub, and read decoding keys from FSR

See merge request !4404

Prepare LHCb v55r2

See merge request !4464

[ci skip]

Updated PLUME decoding in HLT2

See merge request !4435

Allow unknown locations when unpacking for tistos

See merge request !4445

Introduce number of track parameters in TrackParameters

See merge request !4450

Fix truth matching persistency bug

See merge request !4453

Fix Allen UT geometry

See merge request !4395

UThit position methods

See merge request !4269

ProtoParticle: avoid comparing SmartRef to 0, use nullptr instead

See merge request !4452