Extend memory tracing for programatic use and to report on max RSS

[poodlewars]

The idea for this is so that we can measure growth in peak RSS in benchmarks. I'll add one to enterprise soon like,

    for (auto _ : state) {
        auto before_sync = util::get_memory_use_summary();
        sync.go();
        auto after_sync = util::get_memory_use_summary();
        uint64_t max_rss_before_mib = before_sync.max_resident.value_ >> 20;
        state.counters["max_rss_before_sync_mib"] = max_rss_before_mib;
        uint64_t max_rss_after_mib = after_sync.max_resident.value_ >> 20;
        state.counters["max_rss_after_sync_mib"] = max_rss_after_mib;
        state.counters["max_rss_growth_during_sync_mib"] = max_rss_after_mib - max_rss_before_mib;
    }

Test output:

(310) ➜  cpp git:(sync_snapshots_mem) ✗ /home/alex/source/arcticdb-enterprise/out/linux-release-build/ArcticDB/cpp/arcticdb/test_unit_arcticdb --gtest_filter=*PrintMemUsage* --gtest_color=no Note: Google Test filter = *PrintMemUsage*
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from Allocator
[ RUN      ] Allocator.PrintMemUsage
[2024-06-04 16:21:17.596] [arcticdb] [debug] /home/alex/source/arcticdb-enterprise/ArcticDB/cpp/arcticdb/util/test/test_tracing_allocator.cpp (TestBody:45) size[95.7Mb] resident[33.6Mb] max_resident[33.6Mb] shared[28.1Mb] text[43.9Mb] data/stack[6.2Mb]
[       OK ] Allocator.PrintMemUsage (0 ms)
[----------] 1 test from Allocator (0 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test suite ran. (0 ms total) [  PASSED  ] 1 test.