test: Add perf test for http client

[xemul]

The test opens a server socket that reads socket up until double CRLF and then responds back with "HTTP/1.1 200 OK host: test" line in a loop. Then runs http client against it measuring time it takes to perform the given amount of requests. It uses in-memory loopback sockets (seastar wrapper around seastar::queue).

[xemul]

upd:

• fixed trash in CMakefile
• removed unused capture on lambda
• added total mallocs stats

[xemul]

@tchaikov , CI fails compiling a file that's not touched by this PR:

[208/360] Building CXX object tests/unit/CMakeFiles/test_unit_rpc.dir/rpc_test.cc.o
FAILED: tests/unit/CMakeFiles/test_unit_rpc.dir/rpc_test.cc.o 
ccache /usr/bin/g++ -DBOOST_ALL_DYN_LINK -DFMT_SHARED -DSEASTAR_API_LEVEL=7 -DSEASTAR_BUILD_SHARED_LIBS -DSEASTAR_DEFERRED_ACTION_REQUIRE_NOEXCEPT -DSEASTAR_DEPRECATED_OSTREAM_FORMATTERS -DSEASTAR_ENABLE_ALLOC_FAILURE_INJECTION -DSEASTAR_HAS_MEMBARRIER -DSEASTAR_HAVE_ASAN_FIBER_SUPPORT -DSEASTAR_HAVE_HWLOC -DSEASTAR_HAVE_NUMA -DSEASTAR_HAVE_SYSTEMTAP_SDT -DSEASTAR_HAVE_URING -DSEASTAR_LOGGER_COMPILE_TIME_FMT -DSEASTAR_LOGGER_TYPE_STDOUT -DSEASTAR_SCHEDULING_GROUPS_COUNT=16 -DSEASTAR_SSTRING -DSEASTAR_TESTING_MAIN -DSEASTAR_TESTING_WITH_NETWORKING=1 -DSEASTAR_TYPE_ERASE_MORE -I/__w/seastar/seastar/tests/unit -I/__w/seastar/seastar/src -I/__w/seastar/seastar/include -I/__w/seastar/seastar/build/dev/gen/include -I/__w/seastar/seastar/build/dev/gen/src -O1 -std=gnu++23 -Wno-maybe-uninitialized -Wno-error=unused-result -fstack-clash-protection -UNDEBUG -Wall -Werror -Wimplicit-fallthrough -Wdeprecated -Wno-error=deprecated -Wno-error=stringop-overflow -Wno-error=array-bounds -Wdeprecated-declarations -Wno-error=deprecated-declarations -ftls-model=initial-exec -gz -MD -MT tests/unit/CMakeFiles/test_unit_rpc.dir/rpc_test.cc.o -MF tests/unit/CMakeFiles/test_unit_rpc.dir/rpc_test.cc.o.d -o tests/unit/CMakeFiles/test_unit_rpc.dir/rpc_test.cc.o -c /__w/seastar/seastar/tests/unit/rpc_test.cc
/__w/seastar/seastar/tests/unit/rpc_test.cc: In lambda function:
/__w/seastar/seastar/tests/unit/rpc_test.cc:1366:89: error: class template argument deduction failed:
 1366 |             return make_ready_future<rpc::tuple<int, long>>(rpc::tuple(1, 0x7'0000'0000L));
      |                                                                                         ^
/__w/seastar/seastar/tests/unit/rpc_test.cc:1366:89: error: call of overloaded 'tuple(int, long int)' is ambiguous
In file included from /usr/include/c++/14/bits/uses_allocator_args.h:39,
                 from /usr/include/c++/14/bits/memory_resource.h:41,
                 from /usr/include/c++/14/string:68,
                 from /usr/include/c++/14/stdexcept:39,
                 from /usr/include/c++/14/system_error:43,
                 from /__w/seastar/seastar/tests/unit/loopback_socket.hh:24,
                 from /__w/seastar/seastar/tests/unit/rpc_test.cc:22:
/usr/include/c++/14/tuple:1970:5: note: candidate: 'std::tuple(_Ts ...)-> seastar::rpc::tuple<T ...> [with T = {int, long int}]'
...

[tchaikov]

lemme check.

[tchaikov]

lemme check.

i can reproduce this with GCC-14 on fedora 40. seems it's related to ADL.

[tchaikov]

@xemul fixed by #2446

[xemul]

Thanks! Rebased the branch