[TRACKING ISSUE] [API-1513] Promote Compact serialization and GenericRecord APIs to stable status

[hz-devops-test]

The tracking issue for the Java side PR.

See hazelcast/hazelcast#21997 for details.

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This PR removes the BETA annotations from the Compact serialization
and GenericRecord related classes.

Also, as planned earlier, the CompactSerializationConfig#enabled
flag is removed, and Compact serialization is made enabled by
default.