Preparing for producer diagnostics

[erikvanoosten]

It has been a long wish to have producer diagnostics. Although these are not really hard to add, the consumer diagnostics are a bit in the way; these already claim some names and make code sharing awkward. Now that we are moving towards zio-kafka 3.0 we can fix these at the cost of some backward incompatibilities.

This PR prepares for the introduction of producer diagnostics by moving the consumer diagnostics specific code out of the diagnostics package, while keeping the sharable code there.

The following changes are proposed (fixable with scalafix):

Old	New
zio.kafka.consumer.diagnostics.Diagnostics	zio.kafka.consumer.Consumer.ConsumerDiagnostics
zio.kafka.consumer.diagnostics.Diagnostics.NoOp	zio.kafka.consumer.Consumer.NoDiagnostics
zio.kafka.consumer.diagnostics.DiagnosticEvent	zio.kafka.consumer.ConsumerDiagnosticEvent
zio.kafka.consumer.diagnostics.DiagnosticEvent.*	zio.kafka.consumer.ConsumerDiagnosticEvent.*
zio.kafka.consumer.diagnostics.DiagnosticEvent.Finalization.*	zio.kafka.consumer.ConsumerDiagnosticEvent.*

Move to internal or test package:

Old	New	New location
zio.kafka.consumer.diagnostics.Diagnostics.SligingQueue	zio.kafka.utils.SlidingDiagnostics[ConsumerDiagnostics]	zio-kafka-tests
zio.kafka.consumer.diagnostics.Diagnostics.ConcurrentDiagnostics	zio.kafka.diagnostics.internal.ConcurrentDiagnostics	internal
zio.kafka.consumer.diagnostics.DiagnosticEvent.Finalization	removed	-

Notes:

• We can decide to keep SligingQueue public.
• The intermediate trait DiagnosticEvent.Finalization was removed from the type hierarchy because it doesn't serve any user purpose (it was introduced to make it easier to test the shutdown sequence of the consumer).