Add semantics to property-declaration of several components. Implies moving the property declaration to the header file

Additional patterns to ignore to fix test failures in master.
Also, be more specific in suppressing ubsan warnings.

Extend WriteCondHandle::isValid to allow also returning the corresponding
IOV range.

Make the internal (non-templated) TEvent::record method public,
to allow calling it from python.

Fixes failure in DataModelRunTests.

Performance optimization for the case when no cut mask and/or weight is
being used. Use lambda's wherever possible instead of function pointers
to take advantage of compiler optimizations.

Add a test executable that can be used for performance testing and
profiling.

Allow the creation of "rebinable" 2D histograms. Implementation-wise
this is handled by converting the existing `HistogramFillerRebinable1D`
class into a "Mixin" class that is templated with the base class (1D or
2D) and the histogram axis that is supposed to be rebinable.

Typedefs are provided to handle the existing 1D case and the three new
cases to rebin 2D histograms along x, y and both axes. An additional
unit test suite for the 2D case has been added.

Allow inserting a range with an open-ended timestamp part into
a mixed container.

`set` is not callable.

Since those projects don't build enough of the EDM to run this test.

Change IIOVDbSvc::getRange() and IIOVSvc::getRangeFromDB() to return
the address by unique_ptr.

Fix a couple memory leaks in IOVSvc::createCondObj.

The address returned from getRangeFromDB was leaked.
Fixed by changing this method to return the address via a unique_ptr.

An object is read via StoreGateSvc::createObj.  This returns a DataObject*,
which is a DataBucket holding the actual payload object.
The payload object is added to the conditions container, but the
DataBucket is leaked.  Fixed to make sure the DataBucket is freed.

Although clang now supports function multiversioning, it does not
(as of clang 9) support the target_clones attribute.
Add HAVE_TARGET_CLONES to distinguish this.

Delete unused file (this has been moved to AthenaMonitoringKernel).

Fix and unit testing for the following use-case:
```
Monitored::Scalar<std::string>( "DetID", [&](){return "SCT";} );
```
Filling from a generated string was not supported and instead of a
compiler error it actually made the code crash because it tried to
initialize a string from a double (e.g. `std::string m_value(0)`).

Plus undoing an update in a test that was only making the code less
modern.

- Now the diff option does not treat as different 'True' vs True.
- In case of different order in lists that fact is printed instead of printing diff of each of its elements

The xAODRootAccess package also uses that name in a standalone
build to refer to a different class than xAOD::TActiveEvent.
Which ROOT's dictionaries really don't like at runtime. :-P

Merged in all the updates that were done in 21.2 in the last
~2 years. In many cases in a way that required changes in both
the 21.2 and the master code.

Removed all the unit test reference files, as they are much more
of a nuance than how much good they do. :-/

TClassEditRootUtils.h is a version of TClassEdit.h adjusted to avoid
a clang9 bug.  If we use this file with clang9, be sure that we also
don't include the original TClassEdit.h.

Use TClassEditRootUtils.h to work around a clang9 bug.

With minimal modifications necessary for the newer CMake setup
of this branch.

This reverts merge request !31170