Increase Membership Java code quality to facilitate future upgrades/maintenance

Objectives:

• Reduce technical debt
• Improve code stability
• Increase API maintainability

The Goals:

• Add Sonarcloud bindings
• Bring our test coverage to a minimum of 50%
• Reduce code smell by 30% or down to 5 per 1k LOC
• Improve comment coverage to a minimum of 10%
• Ensure no security flaws in our code