fix: Add HU simplified 2-phase version, refactor IHU implementation and fix bugs where possible, change phase/component flux logic #10001

Job	Run time
semantic_pull_request	2s
is_not_draft_pull_request	4s
are_submodules_in_sync	8s
baseline_log	6s
if_not_unassigned_pull_request	2s
code_coverage / build_test_deploy	4s
Check code style / build_test_deploy	1m 28s
Check documentation / build_test_deploy	1m 19s
Ubuntu (20.04, gcc 9.4.0, open-mpi 4.0.3) / build_test_deploy	10m 28s
Sherlock CPU (centos 7.9.2009, gcc 10.1.0, open-mpi 4.1.2, openblas 0.3.10) / build_test_deploy	13m 58s
Ubuntu (20.04, gcc 10.5.0, open-mpi 4.0.3) - github codespaces / build_test_deploy	9m 46s
Ubuntu (22.04, clang 15.0.7, open-mpi 4.1.2) / build_test_deploy	8m 48s
Ubuntu (22.04, gcc 11.4.0, open-mpi 4.1.2) / build_test_deploy	10m 59s
Ubuntu (22.04, gcc 12.3.0, open-mpi 4.1.2) / build_test_deploy	9m 59s
Ubuntu debug (20.04, gcc 10.5.0, open-mpi 4.0.3) - github codespaces / build_test_deploy	14m 56s
Pangea 3 CUDA (AlmaLinux 8.8, gcc 9.4.0, open-mpi 4.1.2, cuda 11.5.0, openblas 0.3.10) / build_test_deploy	6s
Rockylinux CUDA (8, clang 17.0.6, cuda 12.5.1) / build_test_deploy	8s
Rockylinux CUDA (8, gcc 8.5, cuda 12.5.1) / build_test_deploy	6s
Sherlock GPU (centos 7.9.2009, gcc 10.1.0, open-mpi 4.1.2, openblas 0.3.10, cuda 12.4.0,) / build_test_deploy	6s
Ubuntu CUDA (20.04, clang 10.0.0 + gcc 9.4.0, open-mpi 4.0.3, cuda-11.8.89) / build_test_deploy	8s
Ubuntu CUDA debug (20.04, clang 10.0.0 + gcc 9.4.0, open-mpi 4.0.3, cuda-11.8.89) / build_test_deploy	6s
run_integrated_tests / build_test_deploy	6s
check_that_all_jobs_succeeded	1s
	1h 22m 54s

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