Add integration tests for the JMX Metric Gatherer to cover SSL scenarios

[dmitchnewrelic]

Is your feature request related to a problem? Please describe.
The JMX Metric Gatherer doesn't have any integration tests involving SSL.

Describe the solution you'd like
Add integration tests that cover the following scenarios:

• SSL enabled for JMX, but not on the RMI registry
• SSL enabled for JMX including the RMI registry

Describe alternatives you've considered
The alternative is to test this manually when needed.

Additional context
This is related to issue #834 and PR #835

[breedx-splk]

@dmitchnewrelic Is this something you have interest and availability to take on?

[SylvainJuge]

JMX Gatherer is being deprecated and replaced with JMX Scraper which already includes equivalent tests with SSL/TLS scenarios in JmxConnectionTest.java.

Given JMX Gatherer is deprecated and there hasn't had any update on this issue in 2 years, it is quite unlikely that it will be implemented, thus I'll close the issue. Feel free to re-open/comment if needed.