Offload sampling data (#190)

- update timemory submodule
  - support for load/save of ring_buffers
  - new output keys, e.g. `%nid%`
  - sampling allocator offloading data
- writing sampling data to temporary file
- new advanced config option `OMNITRACE_USE_TEMPORARY_FILES`
- new advanced config option `OMNITRACE_TMPDIR`
- SIGINT signal (i.e. `Ctrl+C`) triggers backtrace + finalization
  - this behavior is common to other profilers

* update output.md docs

* Update omnitrace-avail output keys handling

* update writing metadata

* str format in perfetto_counter_track

* Fix fail regex for mpi-example

* config updates

- OMNITRACE_USE_TEMPORARY_FILES
- OMNITRACE_TMPDIR
- Enable finalization with SIGINT
- code supporting creation of temp files

* sampling offloading to temporary file

* Disable creation of empty temporary files when off

source/lib/omnitrace/library.cpp

@@ -991,9 +991,10 @@ omnitrace_finalize_hidden(void)
         OMNITRACE_VERBOSE_F(1, "Finalizing timemory...\n");
         tim::timemory_finalize(_timemory_manager.get());
 
+        auto _cfg       = settings::compose_filename_config{};
+        _cfg.use_suffix = true;
         _timemory_manager->write_metadata(settings::get_global_output_prefix(),
-                                          "omnitrace",
-                                          settings::default_process_suffix());
+                                          "omnitrace", _cfg);
     }
 
     if(_perfetto_output_error)