Add NatsClient to DI

[mtmk]

This change modifies the default serializer and pending policy, hence it is technically a breaking change.

resolves #687

[rickdotnet]

These changes look good to me.

Does it make sense to keep AddJsonSerialization(...) around anymore? Seems confusing and since it now defaults to JSON, I'm not sure that it's needed. There is documentation for NatsJsonContextSerializerRegistry, could expand on that, if necessary. That combined with WithSerializerRegistry() should be the same functionality. If you wanted to keep the method, I'd still suggest renaming it to WithJsonSerializerContext(params JsonSerializerContext[]) and track it in a similar way and take out the chained options.

[mtmk]

These changes look good to me.

Does it make sense to keep AddJsonSerialization(...) around anymore? Seems confusing and since it now defaults to JSON, I'm not sure that it's needed. There is documentation for NatsJsonContextSerializerRegistry, could expand on that, if necessary. That combined with WithSerializerRegistry() should be the same functionality. If you wanted to keep the method, I'd still suggest renaming it to WithJsonSerializerContext(params JsonSerializerContext[]) and track it in a similar way and take out the chained options.

@rickdotnet good point. I know I marked this as breaking already (actually not breaking compiler but behaviour) but do you think we'd upset a lot of code bases if we removed the method. hmm maybe obsolete the old one and keep it around for a while whether we introduce a new method or not?

[rickdotnet]

Safest bet, in my opinion, would be to mark it as obsolete and include a nudge in the right direction, either a new method or a link to docs.