XAR extensions embedded in the hsqldb/jetty distribution are not listed as such

That's because there is no way to "discover" them when looking at the database and those extension are imported into the generated database as simple XAR files.

There is several possibilities:

• put "marker" (use the application descriptor from application-manager for example) in all of them to be able to easily find them
• generated an extension index (like we generate the database) at build time with those extensions