Make the Alpaka implementation of the pixel unpacker skip spurious ROCs,
similar to the legacy and CUDA versions of the unpacker, and store the
invalid ROC number error (errorType=36).

Disable printf statements at compile time.

Use named constants instead of magic numbers.

Rewrite loops using cms::alpakatools::independent_groups(acc, ...) and
independent_group_elements(acc, ...).

Rename variables and improve comments to help readability.

Rewrite loops using cms::alpakatools::independent_groups(acc, ...) and
independent_group_elements(acc, ...).

General clean up.

Renumber the ECAL-only alpaka workflow from ##.411 to ##.412, for
consistency with the old gpu workflows (##.512) and the other alpaka
workflows.

Add pixel-only and ECAL-only alpaka workflows to the set of GPU relvals.

Do not call the fishbone for quasi-empty events, with pixel hits only in
the innermost layer.

Clean up the implementation of the fishbone.

Extend TrackingRecHits collections for testing and their unit tests.

Co-authored-by: Adriano Di Florio <adriano.di.florio@cern.ch>

Generalise elements_with_stride, blocks_with_stride and elements_in_block to
work on any single dimension, and rename them to uniform_elements_along,
uniform_groups_along and uniform_group_elements_along.

Introduce uniform_elements[_x|_y|_z], uniform_groups[_x|_y|_z] and
uniform_group_elements[_x|_y|_z] as specialisations of uniform_elements_along,
uniform_groups_along and uniform_group_elements_along.

Reintrouce elements_with_stride, blocks_with_stride, elements_in_block as
legacy names for uniform_elements, uniform_groups, and uniform_group_elements.

Rename elements_with_stride_nd to uniform_elements_nd, and reintroduce
elements_with_stride_nd as a legacy name for uniform_elements_nd.

Update the unit tests accordingly.

Generalise independent_groups and independent_group_elements to work on any single
dimension, and rename them to independent_groups_along and independent_group_elements_along.

Introduce independent_groups[_x|_y|_z] and independent_group_elements[_x|_y|_z]
as specialisations of independent_groups_along and independent_group_elements_along.

Rewrite the alpaka pixel clustering and rechit-building code using the uniform
and independent kernel utilities from cms::alpakatools.

Rewrite the alpaka pixel seeding code using the uniform and independent kernel
utilities from cms::alpakatools.