Change the extraction functions in orhestrator/stage1 to take `Buf` #799

Job	Run time
build_attest_all (buildconfigs/key_xor_test_app.sh)	41m 47s
build_attest_all (buildconfigs/oak_client_android_app.sh)	50m 0s
build_attest_all (buildconfigs/oak_containers_agent.sh)	34m 31s
build_attest_all (buildconfigs/oak_containers_kernel.sh)	33m 48s
build_attest_all (buildconfigs/oak_containers_orchestrator.sh)	49m 6s
build_attest_all (buildconfigs/oak_containers_stage1.sh)	48m 38s
build_attest_all (buildconfigs/oak_containers_syslogd.sh)	48m 25s
build_attest_all (buildconfigs/oak_containers_system_image.sh)	50m 18s
build_attest_all (buildconfigs/oak_containers_nvidia_system_image.sh)	51m 37s
build_attest_all (buildconfigs/oak_echo_enclave_app.sh)	41m 29s
build_attest_all (buildconfigs/oak_echo_raw_enclave_app.sh)	41m 17s
build_attest_all (buildconfigs/oak_functions_enclave_app.sh)	41m 23s
build_attest_all (buildconfigs/oak_functions_insecure_enclave_app.sh)	42m 12s
build_attest_all (buildconfigs/oak_orchestrator.sh)	41m 3s
build_attest_all (buildconfigs/oak_restricted_kernel_simple_io_init_rd_wrapper_bin.sh)	42m 11s
build_attest_all (buildconfigs/stage0_bin.sh)	41m 30s
build_attest_all (buildconfigs/stage0_bin_tdx.sh)	41m 37s
	12h 20m 52s

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