feat(streaming_client): add --rpc-port flag to ola_streaming_client

Closes #1994 for the streaming-client tool. The RPC port has been
tuneable on olad via -r/--rpc_port since forever (olad/OlaServer.cpp:66);
this exposes the same knob on ola_streaming_client so users can point
the CLI at a non-default olad instance without needing to edit config.

The underlying StreamingClient::Options.server_port field already exists
(ola/StreamingClient.cpp:48,58) and flows through to
ConnectToServer(m_server_port). This PR only surfaces it via the CLI:

- New DEFINE_s_uint16(rpc_port, r, ola::OLA_DEFAULT_PORT, ...) matching
  olad's flag name, short form, and default (9010 from
  include/ola/Constants.h:68).
- Existing 'StreamingClient ola_client;' replaced with an Options
  construction that carries FLAGS_rpc_port.

ola_dmxmonitor and ola_dmxconsole use OlaClientWrapper, which does not
yet carry a server_port knob. Extending the wrapper is a separate
change; this PR is intentionally scoped to the one tool where the
library already supports the option.

Author: mvanhorn

examples/ola-streaming-client.cpp

@@ -19,6 +19,7 @@
  */
 
 #include <stdlib.h>
+#include <ola/Constants.h>
 #include <ola/DmxBuffer.h>
 #include <ola/Logging.h>
 #include <ola/client/StreamingClient.h>
@@ -47,6 +48,8 @@ DEFINE_s_default_bool(universe_from_stdin, s, false,
                       "when reading DMX data from STDIN. The universe number "
                       "must precede the channel values, and be delimited by "
                       "whitespace, e.g. 1 0,255,128 2 0,255,127");
+DEFINE_s_uint16(rpc_port, r, ola::OLA_DEFAULT_PORT,
+                "The RPC port olad is listening on.");
 
 bool terminate = false;
 
@@ -76,7 +79,9 @@ int main(int argc, char *argv[]) {
                "Send DMX512 data to OLA. If DMX512 data isn't provided, it "
                "will read from STDIN.");
 
-  StreamingClient ola_client;
+  StreamingClient::Options options;
+  options.server_port = FLAGS_rpc_port;
+  StreamingClient ola_client(options);
   if (!ola_client.Setup()) {
     OLA_FATAL << "Setup failed";
     exit(ola::EXIT_SOFTWARE);