refactor!: Use enum class for NavigationDirection

[paulgessinger]

This change is motivated by arithmetic between non-class enums and other types that are not the same enum is deprecated in C++20. I overload the operators we use these enums in to support the same use cases.

I think this is breaking since it's part of the public propagator interface.

BREAKING CHANGE: The NavigationDirection enum changes to enum class. The values are renamed NavigationDiretcion::forward -> NavigationDirection::Forward and NavigationDirection::backward -> NavigationDirection::Backward.

[codecov]

Codecov Report

Merging #1206 (51a6476) into main (65d1e09) will increase coverage by 0.09%.
The diff coverage is 59.72%.

@@            Coverage Diff             @@
##             main    #1206      +/-   ##
==========================================
+ Coverage   47.85%   47.94%   +0.09%     
==========================================
  Files         372      373       +1     
  Lines       19439    19495      +56     
  Branches     9148     9152       +4     
==========================================
+ Hits         9302     9347      +45     
- Misses       3806     3817      +11     
  Partials     6331     6331              

Impacted Files	Coverage Δ
Core/include/Acts/Propagator/AtlasStepper.hpp	68.51% <ø> (-0.04%)	⬇️
Core/include/Acts/Propagator/EigenStepper.hpp	68.42% <ø> (-0.81%)	⬇️
.../include/Acts/Propagator/MultiEigenStepperLoop.hpp	70.18% <ø> (ø)
Core/include/Acts/Propagator/Navigator.hpp	53.59% <ø> (ø)
Core/include/Acts/Propagator/Propagator.hpp	89.74% <ø> (ø)
Core/include/Acts/Propagator/StandardAborters.hpp	76.59% <ø> (ø)
...re/include/Acts/Propagator/StraightLineStepper.hpp	67.85% <ø> (-0.57%)	⬇️
Core/include/Acts/TrackFitting/detail/GsfUtils.hpp	52.38% <ø> (ø)
Core/src/Definitions/Common.cpp	0.00% <0.00%> (ø)
Core/src/TrackFitting/GainMatrixUpdater.cpp	11.11% <0.00%> (ø)
... and 26 more

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[stephenswat]

Massive support for going to type-safe enums here, just a few comments where I think find-replace might have gone wrong.

[asalzburger]

There have been some replace errors that can/should be fixed.

[paulgessinger]

I updated the branch and fixed the bad replaces.

[stephenswat]

Looks good to me. Can't close the conversations I opened for some reason, though.

Stephen approved the more recent changes.