[EO12] Messaging Guide: Create chapter about messaging statistics

Documentation does not contain info about statistics which can be obtained from ActiveMQ messaging subsystem. We should document how to configure it and what data it exactly provides

We should include

• how it is enabled - /subsystem=messaging-activemq/server=default:write-attribute(name=statistics-enabled,value=true
• how it is configured - attributes message-counter-max-day-history, message-counter-sample-period
• where it can be obtained - in CLI operations on queue :list-message-counter-as-json, :list-message-counter-as-html, :list-message-counter-history-as-json, :list-message-counter-history-as-html
• how can we reset it - in CLI operation on queue :reset-message-counter
• what does statistics include - it includes Artemis message counters - for description of attributes see [Message counters in upstream docs | https://activemq.apache.org/artemis/docs/1.0.0/management.html#message-counters)
• we should note it may have negative performance impact, so it is disabled by default. However basic information as number of messages on queue, or number of added messages to queue can be obtained using queue attributes without need to set statistics-enabled to true.