Add dispose and timeouts to producer tests.
Add dispose and timeouts to producer tests.

Trying to bring tests into a better state with consistency.

PKRoma/kafka-net,Jroland/kafka-net,martijnhoekstra/kafka-net,bridgewell/kafka-net,BDeus/KafkaNetClient,geffzhang/kafka-net,EranOfer/KafkaNetClient,nightkid1027/kafka-net,CenturyLinkCloud/kafka-net,aNutForAJarOfTuna/kafka-net,gigya/KafkaNetClient