Refactor cmake (#1231)

Fixes #920.

src/util/CMakeLists.txt

@@ -0,0 +1,44 @@
+add_library(clio_util)
+
+target_sources(
+  clio_util
+  PRIVATE config/Config.cpp
+          log/Logger.cpp
+          prometheus/Http.cpp
+          prometheus/Label.cpp
+          prometheus/MetricBase.cpp
+          prometheus/MetricBuilder.cpp
+          prometheus/MetricsFamily.cpp
+          prometheus/OStream.cpp
+          prometheus/Prometheus.cpp
+          Random.cpp
+          Retry.cpp
+          requests/RequestBuilder.cpp
+          requests/Types.cpp
+          requests/WsConnection.cpp
+          requests/impl/SslContext.cpp
+          Taggable.cpp
+          TerminationHandler.cpp
+          TxUtils.cpp
+          LedgerUtils.cpp
+)
+
+target_link_libraries(
+  clio_util
+  PUBLIC Boost::headers
+         Boost::stacktrace_backtrace
+         dl
+         libbacktrace::libbacktrace
+         fmt::fmt
+         openssl::openssl
+         xrpl::libxrpl
+         Threads::Threads
+         clio_options
+)
+
+if (is_gcc)
+  # FIXME: needed on gcc for now
+  #
+  # For some reason cmake doesn't propagate the compile definitions from clio_options so we need to add them here
+  target_compile_definitions(clio_util PUBLIC BOOST_ASIO_DISABLE_CONCEPTS)
+endif ()