C++ put test types out of the SDK and into the test executable

[Wumpf]

• Part of C++ SDK V1 #2919
• Depends on C/C++ errorhandling #3001
• Solves C++ part of Exclude mock archetypes/datatypes/components from release artifacts #2537

What

Moves out all affix-fuzzer and co. testing types of the actual SDK.

While working on that...

• I figured out why warnings from arrow headers showed up only sometimes: When Arrow isn't added explicitely as a dependency, CMake doesn't seem to declare it as system header which normally suppresses warnings (as you can imagine this got really bad now when adding more cpps that include arrow to the test library). Obvious workaround is to add arrow explicitly to the text executable.
• internal include paths got shorter/more natural in some cases. I had to make the Includes utility more clever in order to support types outside of the sdk, so we got this almost for free :)

Checklist

• I have read and agree to Contributor Guide and the Code of Conduct
• I've included a screenshot or gif (if applicable)
• I have tested demo.rerun.io (if applicable)

• PR Build Summary
• Docs preview
• Examples preview

[jleibs]

Much cleaner!

[github-actions]

Size changes

Name	Previous	Current	Change
Wasm	(none)	13.499 MB	+100%
JS	(none)	107.698 KB	+100%
arkit_scenes.rrd	(none)	41660.537 KB	+100%
detect_and_track_objects.rrd	(none)	59524.213 KB	+100%
dicom_mri.rrd	(none)	64877.032 KB	+100%
dna.rrd	(none)	781.585 KB	+100%
human_pose_tracking.rrd	(none)	56968.432 KB	+100%
plots.rrd	(none)	258.045 KB	+100%
structure_from_motion.rrd	(none)	7083.767 KB	+100%