[uxrce_dds_client] add minimal request-reply support #21149

Job	Run time
build (check_format)	1m 2s
build (tests)	7m 38s
build (tests_coverage)	8m 10s
build (px4_fmu-v2_default stack_check)	3m 17s
build (validate_module_configs)	1m 1s
build (shellcheck_all)	1m 37s
build (NO_NINJA_BUILD=1 px4_fmu-v5_default)	6m 5s
build (NO_NINJA_BUILD=1 px4_sitl_default)	5m 20s
build (airframe_metadata)	1m 17s
build (module_documentation)	1m 21s
build (parameters_metadata)	1m 27s
	38m 15s

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