- move Gaudi::Funtional to GaudiFunctional subdir
  - headers are now under "Gaudi/Functional"
  - legacy GaudiAlg corresponding header redirect to the new ones
- replace GaudiAlgorithm with Algorithm wherever possible in tests and
  utilities
- add Gaudi::Sequencer basic implementation to replace GaudiSequencer
- move GaudiAlg specific tests, examples, dictionaries and Python modules
  to GaudiAlg subdir
- add CMake option GAUDI_ENABLE_GAUDIALG to allow skipping GaudiAlg
  (default to true)
- minor fixes and clean ups

See merge request !1472

See merge request gaudi/Gaudi!1475

See merge request gaudi/Gaudi!1476

only showing on el9 gcc12

- change default LCG to 103
- run build and test in one job
- test centos7 and el9
- use LCG 102b x86_64-centos7-gcc11-opt as minimum version

See merge request gaudi/Gaudi!1474

adding a test to make sure we compile an instantiation of it

See merge request gaudi/Gaudi!1469

Closes #262

See merge request gaudi/Gaudi!1467

See merge request gaudi/Gaudi!1466

See merge request gaudi/Gaudi!1465

See merge request gaudi/Gaudi!1464

See merge request gaudi/Gaudi!1461

See merge request gaudi/Gaudi!1460

See merge request gaudi/Gaudi!1462

If `QMTEST_DISABLE_FIXTURES_REQUIRED` is truthy, a failing prerequisite
test will not cause the test depending on it to be skipped.

Workaround for #216

the additions of decltype checks in Gaudi::Property are needed to avoid
that fmtlib confuses Gaudi::Property for a range.

And added a test checking new behavior.
Basically integer arithmetic was broken as the index computation was optimized by precomputing the bin width. This lead to 0 bin width when < 1. Now fixed.

Essentially to be able to inspect the configuration of histograms, e.g. nb bins, min/max value, etc
These methods were so far protected for unknown reasons

See merge request gaudi/Gaudi!1459

See merge request !1456

Closes #266

See merge request !1455

See merge request !1457