cam_test: add `B` key to toggle HDR exposure base, #3262

Job	Run time
build-docstrings	2m 41s
pytest (ubuntu-latest)	6m 38s
build-linux-armhf (rpi-bookworm)	1s
build-linux-armhf (rpi-bullseye)	57m 58s
pytest (windows-latest)	43m 30s
build-macos (3.9, macos-14)	9m 25s
build-macos (3.10, macos-14)	5m 9s
build-linux-x86_64	39m 35s
build-macos (3.11, macos-14)	6m 30s
build-macos (3.10, macos-13)	25m 2s
pytest (macos-14)	9m 37s
build-macos (3.8, macos-14)	5m 26s
build-macos (3.12, macos-14)	7m 9s
build-macos (3.9, macos-13)	32m 48s
build-windows-x86_64 (3.7, x64)	22m 17s
build-macos (3.13, macos-14)	4m 54s
build-linux-arm64	34m 28s
build-macos (3.11, macos-13)	33m 30s
build-windows-x86_64 (3.8, x64)	22m 12s
build-windows-x86_64 (3.7, x86)	24m 27s
build-macos (3.13, macos-13)	34m 55s
build-macos (3.12, macos-13)	23m 17s
build-macos (3.8, macos-13)	25m 30s
build-windows-x86_64 (3.8, x86)	25m 22s
build-windows-x86_64 (3.9, x64)	21m 9s
build-windows-x86_64 (3.13, x64)	21m 56s
build-windows-x86_64 (3.9, x86)	22m 25s
build-windows-x86_64 (3.11, x86)	22m 21s
build-windows-x86_64 (3.13, x86)	22m 57s
build-windows-x86_64 (3.10, x64)	22m 12s
build-windows-x86_64 (3.12, x86)	24m 8s
build-windows-x86_64 (3.11, x64)	22m 41s
build-windows-x86_64 (3.10, x86)	23m 57s
build-windows-x86_64 (3.12, x64)	22m 2s
notify_hil_workflow	-1s
deploy	-1s
release	-1s
	12h 8m 6s

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