Refactor PartitionsSaxHandler to use boost::json #2226

Job	Run time
PSV.Linux.Android.22.04	8m 42s
PSV.Linux.22.04.gcc9.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	2m 40s
PSV.Linux.22.04.gcc11.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	2m 36s
PSV.Linux.22.04.gcc9.Cpplint	11s
PSV.Linux.22.04.gcc11.OLP_SDK_NO_EXCEPTION=ON	7m 0s
PSV.Linux.24.04.gcc13.Tests	7m 51s
PSV.Linux.22.04.gcc9.Tests.CodeCov	10m 25s
PSV.Linux.latest.gcc14.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	2m 30s
PSV.MacOS15.Xcode16.ARM64	3m 44s
PSV.Linux.22.04.gcc11	8m 36s
PSV.iOS.MacOS14.Xcode15.ARM64	5m 51s
PSV.Linux.22.04.clang	9m 0s
PSV.Commit.Checker	13s
PSV.iOS.MacOS15.Xcode16.ARM64	6m 28s
PSV.Clang.Format.Checker	39s
PSV.iOS.MacOS15.Xcode26.ARM64	7m 48s
PSV.Win.VC2022	11m 2s
	1h 35m 16s

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