Fixed test flakniess due to indeterminate HashMap ordering

Description
The test testInvocationOnMixedModeCluster() in MixedModeServiceURLTestCase.java can fail nondeterministically. The issue is found using Nondex when running commands
mvn edu.illinois:nondex-maven-plugin:1.1.2:nondex -Dtest=MixedModeServiceURLTestCase under javax directory after building all dependencies. The problem is in the function validateResults() that deals with ServiceURL. In NodeInformation.java, the code calls ServiceURL.Builder.create() (e.g. line 216), which uses the default iterator of a HashMap.entrySet(). An EntrySet of a normal HashMap does not guarantee any order. Therefore, serviceURL may have internal order permutation. When toString() is called, a sample output String can be "service:ejb.jboss:remote://localhost:7099;node=node2;cluster=mixed-ejb;ejb-module=my-foo-app/my-bar-module" in one run, and then "service:ejb.jboss:remote://localhost:7099;cluster=mixed-ejb;node=node2;ejb-module=my-foo-app/my-bar-module" in another run. These possibilities can make the unit test fail occasionally.

Reasons for Fixing
The test may fail been run in a different enviornment or when Java upgrades in the future.

Fixes
Split the String formatted ServiceURL by semicolon. Then convert the output String Array into a HashSet to allow order permutation. Then do a direct comparison between the nested HashSets.