"ODE" quantities and user defined external sources #599

Job	Run time
Formatting	10s
Save-PR-Number	4s
Lint-codeql	5m 27s
CPU-GNUmake	3m 58s
CPU-CMake (ubuntu-latest, Release, EB-OFF)	5m 17s
Lint-clang-tidy (EB-OFF)	5m 21s
CPU-CMake (ubuntu-latest, Release, EB-ON)	5m 16s
Lint-clang-tidy (EB-ON)	5m 23s
Lint-codespell	6s
CPU-CMake (ubuntu-latest, Debug, EB-OFF)	5m 18s
CPU-CMake (ubuntu-latest, Debug, EB-ON)	5m 17s
CPU-CMake (macos-latest, Release, EB-OFF)	5m 21s
CPU-CMake (macos-latest, Release, EB-ON)	5m 18s
GPU-SYCL	1m 8s
GPU-HIP	1m 8s
GPU-CUDA (11.4)	1m 8s
	55m 40s

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