Add MessagePack item serializer and validator #1731

Job	Run time
Validate Steward Config (ubuntu-latest, temurin@11)	18s
Submit Dependencies	0s
Build and Test (ubuntu-latest, 2.12, temurin@11, rootJS)	5m 43s
Generate Site (ubuntu-latest, temurin@11)	1m 55s
Build and Test (ubuntu-latest, 2.12, temurin@11, rootJVM)	4m 20s
Build and Test (ubuntu-latest, 2.12, temurin@11, rootNative)	8m 25s
Build and Test (ubuntu-latest, 2.13, temurin@11, rootJS)	5m 40s
Build and Test (ubuntu-latest, 2.13, temurin@11, rootJVM)	4m 14s
Build and Test (ubuntu-latest, 2.13, temurin@11, rootNative)	8m 29s
Build and Test (ubuntu-latest, 3, temurin@11, rootJS)	6m 29s
Build and Test (ubuntu-latest, 3, temurin@11, rootJVM)	4m 29s
Build and Test (ubuntu-latest, 3, temurin@11, rootNative)	8m 56s
Publish Artifacts	0s
	58m 58s

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