test: add is_bitcoin_util_compiled helper

test/config.ini.in

@@ -19,6 +19,7 @@ RPCAUTH=@abs_top_srcdir@/share/rpcauth/rpcauth.py
 @USE_SQLITE_TRUE@USE_SQLITE=true
 @USE_BDB_TRUE@USE_BDB=true
 @BUILD_BITCOIN_CLI_TRUE@ENABLE_CLI=true
+@BUILD_BITCOIN_UTIL_TRUE@ENABLE_BITCOIN_UTIL=true
 @BUILD_BITCOIN_WALLET_TRUE@ENABLE_WALLET_TOOL=true
 @BUILD_BITCOIND_TRUE@ENABLE_BITCOIND=true
 @ENABLE_FUZZ_TRUE@ENABLE_FUZZ=true