Refactor PartitionsSaxHandler to use boost::json #2225

Job	Run time
PSV.Linux.22.04.gcc9.Tests.CodeCov	10m 33s
PSV.Linux.22.04.gcc11.OLP_SDK_NO_EXCEPTION=ON	7m 23s
PSV.Linux.latest.gcc14.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	2m 29s
PSV.Linux.24.04.gcc13.Tests	8m 7s
PSV.Linux.22.04.gcc9.Cpplint	9m 10s
PSV.Linux.22.04.gcc11	8m 19s
PSV.Linux.22.04.gcc9.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	2m 43s
PSV.Win.VC2022	9m 31s
PSV.MacOS15.Xcode16.ARM64	4m 52s
PSV.Linux.22.04.gcc11.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	2m 48s
PSV.iOS.MacOS14.Xcode15.ARM64	5m 18s
PSV.Linux.22.04.clang	8m 27s
PSV.Clang.Format.Checker	34s
PSV.Commit.Checker	7s
PSV.iOS.MacOS15.Xcode16.ARM64	6m 59s
PSV.Linux.Android.22.04	6m 52s
PSV.iOS.MacOS15.Xcode26.ARM64	7m 37s
	1h 41m 49s

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