SONAR-13444 Add support for new type of background task

sonar-core/src/main/resources/org/sonar/l10n/core.properties

@@ -2630,6 +2630,7 @@ background_task.type.ALL=All
 background_task.type.REPORT=Project Analysis
 background_task.type.DEV_REFRESH=Developer Analysis
 background_task.type.DEV_PURGE=Developer Cleaning
+background_task.type.ISSUE_SYNC=Project Data Reload
 
 background_tasks.page=Background Tasks
 background_tasks.page.description=This page allows monitoring of the queue of tasks running asynchronously on the server. It also gives access to the history of finished tasks and their status. Analysis report processing is the most common kind of background task.