feat: union proof type relevant stuff #768

Job	Run time
Test raiko-lib	1m 35s
build-test-native / Build and test native / Build and test	8m 1s
build-test-native / Run integration tests on native / Build and run integration	4m 28s
build-test-risc0 / Build and test risc0 / Build and test	27m 5s
build-test-risc0 / Run integration tests on risc0 / Build and run integration	12m 5s
build-test-sgx-all / Build and test sgx / Build and test	8m 27s
build-test-sgx-all / Build and test sgx with Docker / Build and test sgx with Docker	4m 41s
build-test-sgx-all / Build and test sgx in hardware / Build and test sgx in hardware	18m 47s
build-test-sgx-all / Run integration tests on sgx / Build and run integration	4m 54s
build-test-sp1 / Build and test sp1 / Build and test	23m 14s
build-test-sp1 / Run integration tests on sp1 / Build and run integration	8m 13s
	2h 1m 30s

Provide feedback