to_json refactor

[mikes-lunarg]

This PR is an attempt to move away from FieldToJson overloaded functions for converting GFXR types into nlohmann::ordered_json objects. The clang compiler (particularly on macOS) consumes a lot of memory resolving the large number of FieldToJson overloads in the codebase and has previously forced us to disable the macOS GitHub Actions runners (#2640).

The replacement solution is to define to_json functions for all of the types we want to convert, as described in the nlohmann/json docs: https://github.com/nlohmann/json?tab=readme-ov-file#arbitrary-types-conversions. While it seems similar to the FieldToJson approach, using to_json goes through the nlohmann::adl_serializer and doesn't suffer the same (Many call site)x(Many implementation) explosion in the compiler.

This changeset only migrates enums, flags, and integer types from FieldToJson to to_json as they represent a bulk of the FieldToJson call sites. Other types from the gfxrecon::decode namespace could be added in the future to simplify the code generators and make things more consistent.

Results

For the memory-constrained GitHub runners the change makes a significant difference:

Before:

After:

On higher spec'd developer machines the difference is smaller, but still noticable:

Before

Built 285 targets in 10.15 min total.
   47.24 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_struct_to_json.cpp.o
   31.44 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_replay_consumer.cpp.o
   25.51 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_openxr_struct_to_json.cpp.o
   24.64 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_json_consumer.cpp.o
   13.08 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_openxr_json_consumer.cpp.o
   11.88 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_cpp_structs.cpp.o
   11.62 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_pnext_struct_decoder.cpp.o
    9.82 s framework/decode/CMakeFiles/gfxrecon_decode.dir/vulkan_replay_consumer_base.cpp.o
    9.49 s framework/encode/CMakeFiles/gfxrecon_encode.dir/__/generated/generated_vulkan_pnext_struct_encoder.cpp.o
    9.42 s framework/encode/CMakeFiles/gfxrecon_encode.dir/__/generated/generated_vulkan_api_call_encoders.cpp.o

Peak memory usage: 7079.78 MB
    6277.66 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_struct_to_json.cpp.o
    3311.78 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_json_consumer.cpp.o
    3127.98 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_openxr_struct_to_json.cpp.o
    1849.25 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_openxr_json_consumer.cpp.o
    1477.75 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/vulkan_replay_consumer_base.cpp.o
    1348.52 MB tools/replay/CMakeFiles/gfxrecon-replay.dir/desktop_main.cpp.o
    1289.88 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_pnext_struct_decoder.cpp.o
    1263.95 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_cpp_structs.cpp.o
    1219.22 MB tools/convert/CMakeFiles/gfxrecon-convert.dir/main.cpp.o
    1199.89 MB framework/encode/CMakeFiles/gfxrecon_encode.dir/vulkan_state_writer.cpp.o

After

Built 285 targets in 8.03 min total.
   31.38 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_replay_consumer.cpp.o
   12.14 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_cpp_structs.cpp.o
   11.91 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_pnext_struct_decoder.cpp.o
   10.03 s framework/decode/CMakeFiles/gfxrecon_decode.dir/vulkan_replay_consumer_base.cpp.o
    9.74 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_struct_to_json.cpp.o
    9.60 s framework/encode/CMakeFiles/gfxrecon_encode.dir/__/generated/generated_vulkan_api_call_encoders.cpp.o
    9.57 s framework/encode/CMakeFiles/gfxrecon_encode.dir/__/generated/generated_vulkan_pnext_struct_encoder.cpp.o
    8.05 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_openxr_struct_to_json.cpp.o
    6.98 s framework/encode/CMakeFiles/gfxrecon_encode.dir/__/generated/generated_openxr_api_call_encoders.cpp.o
    6.67 s framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_struct_handle_mappers.cpp.o

Peak memory usage: 3404.72 MB
    1476.06 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/vulkan_replay_consumer_base.cpp.o
    1361.81 MB tools/replay/CMakeFiles/gfxrecon-replay.dir/desktop_main.cpp.o
    1285.27 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_pnext_struct_decoder.cpp.o
    1262.20 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_cpp_structs.cpp.o
    1199.86 MB framework/encode/CMakeFiles/gfxrecon_encode.dir/vulkan_state_writer.cpp.o
    1133.64 MB framework/encode/CMakeFiles/gfxrecon_encode.dir/vulkan_capture_manager.cpp.o
    1098.56 MB framework/encode/CMakeFiles/gfxrecon_encode.dir/__/generated/generated_vulkan_api_call_encoders.cpp.o
    1018.27 MB tools/convert/CMakeFiles/gfxrecon-convert.dir/main.cpp.o
    976.16 MB framework/encode/CMakeFiles/gfxrecon_encode.dir/vulkan_state_tracker.cpp.o
    963.42 MB framework/decode/CMakeFiles/gfxrecon_decode.dir/__/generated/generated_vulkan_replay_consumer.cpp.o```