Unify (de)serializer declarations

[yuanchen233]

Every CORE application service has its own serializer and deserializer which we use in ObjectMapperConfig, but that doesn’t necessarily have to be like that; we can create a generic serializer factory that gets an input type on call, which is the type of object it serializes (or some other solution)

The objective is to not have to create a new serializer/deserializer instance every time there is a new object added to core, but instead where we could just declare the type and that’s it.

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We will use the Kotlin serializers

[davidscavnicky]

This approach solves multiple issues with size of the code base. (repetitive code, same functionality described for classes ..)

[bardram]

Almost done - Needs documentation

[yuanchen233]

All serialization involving core is using Kotlinx.serialization now, with one exception: datastreams,
datastream is saved in database as snapshots, which is not related to core Snapshot.

Some Portal specific endpoint with webservice data type is still using Jackson serializer, this will be fine as long as there is no core data type involved. However, if we want to configure Spring to use kotlinx.serialization by default, all those type need to be annotated with Serializable