Add kotlin.serialization implementation of Serializer

[lion7]

This PR adds support for serializing by using kotlinx.serialization and is basically a continuation of #124.

Note that I had to upgrade the Kotlin version (and fix a few generics in QueryGatewayExtensions.kt) to make it work.

[gklijs]

Looks great from quickly going through it, I'll try to review it this week.

[CLAassistant]

All committers have signed the CLA.

[jangalinski]

Great approach. We are working on a kotlinx.serialization based avro serializer as well and might (re-)use generic features provided by extension-kotlin.
But: kotlinx.serialization is a generic tool for serialization, json is just one aspect. So I would like to have a clearer separation between json-specific and kotlinx-generic features ...

[lion7]

This implementation is already independent of the serialization format. I changed the main dependency to use the core library instead and added a few more tests for binary formats as well.

It should work with any SerialFormat that either implements StringFormat or BinaryFormat.

[gklijs]

I have some questions about Axon Specific classes that needs to be serialized, which are not included in the SerializersModule. All new files should have the copyright notice. It would also be nice if we don't need to opt in for experimental api's. As this is a new feature, it's likely better to set 4.10 as the target.

[zambrovski]

We were playing with KSerializer registration in our Apache Avro approach and came up with a small SPI. By doing so it is pretty easy to write own serializers and let the SPI loader automatically register those.

But before building this, it would be a good idea to document how new KSerializers needs to be registered. In general, do you have any docs describing the implemented features?

[jangalinski]

We were playing with KSerializer registration in our Apache Avro approach and came up with a small SPI. By doing so it is pretty easy to write own serializers and let the SPI loader automatically register those.

But before building this, it would be a good idea to document how new KSerializers needs to be registered. In general, do you have any docs describing the implemented features?

Actually, this part is already public/released ... peek here if you like: https://github.com/toolisticon/avro-kotlin/tree/develop/avro-kotlin-serialization/src/main/kotlin/spi

[smcvb]

Looks fine, although I have a couple of questions and remarks.