Add a registered server method to bad_client

test/core/bad_client/bad_client.c

test/core/bad_client/bad_client.h

test/core/bad_client/tests/badreq.c

test/core/bad_client/tests/connection_prefix.c

test/core/bad_client/tests/headers.c

test/core/bad_client/tests/initial_settings_frame.c

test/core/bad_client/tests/simple_request.c

test/core/bad_client/tests/unknown_frame.c