Rerun 0.12 zombie TODO pass

[teh-cmc]

• ./crates/re_viewer/src/ui/welcome_screen/welcome_page.rs+14: const CPP_SPAWN_MARKDOWN: &str = include_str!("../../../data/quick_start_guides/cpp_connect.md"); // TODO(Add spawn-like functionality to C++ and Rust #3757)
• ./crates/re_viewer/src/ui/welcome_screen/welcome_page.rs+28: include_str!("../../../data/quick_start_guides/quick_start_connect.cpp"); // TODO(Add spawn-like functionality to C++ and Rust #3757)
• ./crates/re_arrow_store/src/store_write.rs+228: // TODO(datastore: implement shared slices for autogenerated keys #1777): shared slices for auto generated keys
• ./crates/re_data_store/src/entity_properties.rs+80: // TODO(EntityProperties need to be "unflattened" #1423): We need to properly split entity properties that only apply to specific
• ./rerun_cpp/src/rerun/collection.hpp+30: /// TODO(C++ universal "maybeowned" adapting container used everywhere instead of std::vector #3794): don't do std::vector
• ./rerun_cpp/src/rerun/collection.hpp+277: /// TODO([C++] Rename rerun::ComponentBatch to rerun::Collection (and related constructs) #4225): So far it always is continuous, but in the future we want to support strides!
• ./rerun_cpp/src/rerun/archetypes/boxes3d.hpp+118: /// TODO(C++ universal "maybeowned" adapting container used everywhere instead of std::vector #3794): This should not take an std::vector.
• ./rerun_cpp/src/rerun/archetypes/boxes3d.hpp+126: /// TODO(C++ universal "maybeowned" adapting container used everywhere instead of std::vector #3794): This should not take an std::vector.
• ./rerun_cpp/src/rerun/archetypes/boxes3d.hpp+140: /// TODO(C++ universal "maybeowned" adapting container used everywhere instead of std::vector #3794): This should not take an std::vector.
• ./rerun_cpp/src/rerun/archetypes/boxes3d_ext.cpp+34: /// TODO(C++ universal "maybeowned" adapting container used everywhere instead of std::vector #3794): This should not take an std::vector.
• ./rerun_cpp/src/rerun/archetypes/boxes3d_ext.cpp+42: /// TODO(C++ universal "maybeowned" adapting container used everywhere instead of std::vector #3794): This should not take an std::vector.
• ./rerun_cpp/src/rerun/archetypes/boxes3d_ext.cpp+56: /// TODO(C++ universal "maybeowned" adapting container used everywhere instead of std::vector #3794): This should not take an std::vector.
• ./rerun_cpp/docs/readme_snippets.cpp+14: // TODO(C++ universal "maybeowned" adapting container used everywhere instead of std::vector #3794): Once image logging is nicer, we should do that in this snippet as well!
• ./rerun_cpp/docs/writing_docs.md+14: TODO(C++ API Docs webpage #3974): get this part working for C++!
• ./rerun_cpp/tests/recording_stream.cpp+131: // TODO(Crash on shutdown when using thread local recording stream, Mac only (?) #2889): Setting thread locals causes a crash on shutdown on macOS.
• ./docs/code-examples/roundtrips.py+29: "quick_start_spawn": ["cpp"], # TODO(Add C++ to in-viewer quick-start guide #3870): Not yet implemented in C++
• ./docs/content/reference/viewer/blueprint.md+43: TODO(#1174): Editable & user defined Data Blueprint Groups
• ./tests/python/gc_stress/many_large_single_row_recordings.py+30: # TODO(Implement recording/last-modified-at aware garbage collection #4183): Investigate this.