Cleanup main model: Clean all includes and make some components to be forward declared #2407

Job	Run time
ci-started	3s
check-code-quality / check-code-quality	11m 4s
build-test-release / Build sdist and set version	19s
reuse-compliance / reuse-compliance-check	15s
clang-tidy / clang-tidy (debug)	58m 15s
build-test-release / build-cpp-test-macos (release)	45s
build-test-release / Build and test in Conda (windows)	4m 0s
clang-tidy / clang-tidy (release)	59m 20s
build-test-release / build-cpp-test-linux (debug, clang)	11m 51s
build-test-release / build-cpp-test-windows (debug, clang-cl)	1m 12s
build-test-release / build-cpp-test-windows (release, msvc)	1m 18s
build-test-release / build-cpp-test-windows (release, clang-cl)	1m 20s
build-test-release / build-cpp-test-linux (release, gcc)	17m 17s
build-test-release / Build and test in Conda (ubuntu)	3m 17s
build-test-release / build-cpp-test-linux (debug, gcc)	17m 16s
build-test-release / build-cpp-test-linux (release, clang)	17m 10s
build-test-release / build-cpp-test-macos (debug)	28s
build-test-release / build-cpp-test-windows (debug, msvc)	1m 16s
build-test-release / build-and-test-python (linux-x64)	1m 15s
build-test-release / build-and-test-python (macos)	1m 0s
build-test-release / build-and-test-python (linux-aarch64)	1m 12s
build-test-release / build-and-test-python (windows)	1m 6s
build-test-release / Create and release assets to GitHub	4s
Publish to PyPI	0s
ci-passed	4s
	3h 31m 7s

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