SONAR-5529 - Created org.sonar.server.issue.index package with required classes (Index, Doc and Normalizer)
SONAR-5529 - Created ISSUES IndexDefinition
SONAR-5529 - IssueDoc is our domain object and must implement Issue (from API)
SONAR-5529 - Fixed BaseIndex for source and updated ES Types for domain objects
SONAR-5529 - Initial materialization of Issues in ES
code format