Move exemplar types to non-internal package #14430

Job	Run time
lint	2m 31s
test-bench	1m 2s
test-race	2m 14s
compatibility-test (1.23.0, ubuntu-latest, 386)	44s
test-concurrent-safe	4m 5s
compatibility-test (1.23.0, ubuntu-latest, amd64)	1m 21s
compatibility-test (1.23.0, macos-13, amd64)	2m 35s
compatibility-test (1.23.0, macos-latest, arm64)	46s
test-coverage	55s
compatibility-test (1.23.0, windows-latest, 386)	2m 41s
compatibility-test (1.23.0, windows-latest, amd64)	2m 6s
compatibility-test (1.23.0, actuated-arm64-2cpu-8gb, arm64)	2m 0s
compatibility-test (~1.22.5, ubuntu-latest, 386)	27s
compatibility-test (~1.22.5, ubuntu-latest, amd64)	1m 10s
compatibility-test (~1.22.5, macos-13, amd64)	1m 50s
compatibility-test (~1.22.5, macos-latest, arm64)	32s
compatibility-test (~1.22.5, windows-latest, 386)	3m 16s
compatibility-test (~1.22.5, windows-latest, amd64)	4m 1s
compatibility-test (~1.22.5, actuated-arm64-2cpu-8gb, arm64)	1m 55s
codecov	7s
test-compatibility	1s
	36m 19s

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