Add HelixRestObjectNameFactory to create namespaced ObjectName

[huizhilu]

Issues

• My PR addresses the following Helix issues and references them in the PR description:

Resolves #1356

Description

• Here are some details about my PR, including screenshots of any UI changes:

We need helix rest service metrics for each namespace. To achieve this, the namespace info needs to be contained in the MBean's object name, eg: domain:name=getClusters,namespace=myNamespace,type=counters. But DropWizard's default ObjectNameFactory doesn't have the namespace parameter.

This PR implements a custom object name factory and add the namespace to object name.

Tests

• The following tests are written for this issue:

TestHelixRestObjectNameFactory

• The following is the result of the "mvn test" command on the appropriate module:

[INFO] Tests run: 167, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 43.615 s - in TestSuite
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 167, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  49.751 s
[INFO] Finished at: 2020-09-11T00:08:46-07:00
[INFO] ------------------------------------------------------------------------

Final run:

[INFO] Tests run: 168, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 39.041 s - in TestSuite
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 168, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  45.121 s
[INFO] Finished at: 2020-09-21T18:16:05-07:00
[INFO] ------------------------------------------------------------------------

Documentation (Optional)

• In case of new functionality, my PR adds documentation in the following wiki page:

(Link the GitHub wiki you added)

Commits

• My commits all reference appropriate Apache Helix GitHub issues in their subject lines. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Code Quality

• My diff has been formatted using helix-style.xml
  (helix-style-intellij.xml if IntelliJ IDE is used)

[huizhilu]

@jiajunwang Thanks for the review and discussion. I've updated the lib version. Also ELR the libs to our internal artifactory to be ready.

[junkaixue]

Left one question. Overall, LGTM. But please address other reviewers concerns.

[huizhilu]

Thank @dasahcc @jiajunwang for the review!

This PR is ready to be merged, approved by @dasahcc @jiajunwang