ARTEMIS-5607 Support disabling JMX notifications

[hyperxpro]

Motivation:

JMX notifications are rarely used these days yet the broker still mirrors all management notifications as JMX notifications. This is unnecessary overhead in most circumstances so we should allow users to disable them.

Modification:

Added a new jmx-notification-enabled boolean configuration property (default true) to allow users to disable the mirroring of management notifications as JMX notifications. When set to false, the NotificationBroadcasterSupport in ManagementServiceImpl is not instantiated, and all JMX notification methods in ActiveMQServerControlImpl short-circuit, eliminating the overhead.

Result:
Fixes ARTEMIS-5607

[clebertsuconic]

• this needs a JIRA
• I'm not sure I like the name of the property on the configuration.. although I'm terrible with names.. I would prefer a name that doesn't not include "enabled" in the property name.

[jbertram]

@hyperxpro, this looks good overall. Nice work! That said, there are a few items that need attention:

1. The commit message should reference the Jira. See here.
2. There is no test that verifies the behavior. I think even a simple unit test that verifies broadcast is null or not when creating an instance of ManagementServiceImpl would be sufficient.
3. I realize now that using the term "mirrors" in Jira description was a mistake because we already have a mirroring feature in the broker and this may cause confusion. You've used this term throughout the JavaDoc and commit message. I think using something like "reproduces" (and variants) would be more clear.

[jbertram]

Regarding the name jmx-notification-enabled, this is consistent with the naming convention used for other settings (e.g. jmx-management-enabled, persistence-enabled, message-counter-enabled, etc.). Therefore, I don't have a problem with the name. In fact, I think it makes more sense to be consistent here rather than use a different convention.

[clebertsuconic]

I guess the only thing missing is the commit with the JIRA id? and a test?

@hyperxpro let me know if you can do? if you can't just let me know and I will do it.

for the JIRA ID you amended the title of the PR, but not the git commit itself. You will need to amend it.

[clebertsuconic]

@hyperxpro please type the following before you make any further changes:

git pull --rebase ARTEMIS-5607

I amended the commit on your branch (It's a feature on github that I can change branch)

[hyperxpro]

@clebertsuconic @jbertram PTAL, aligned everything as requested. :)

[clebertsuconic]

I will run my private CI with the complete testsuite. and if everything is good I will merge this.

thank you.

[clebertsuconic]

I added an additional commit to your branch (a test on broker properties).

[clebertsuconic]

I will add this to releases.adoc

[clebertsuconic]

I meant versions.adoc

[clebertsuconic]

@hyperxpro thank you so much for this contribution.