Don't swallow exception when transaction timeout in GC

The GC binaries task is a very long process that usually timeout on large repositories.

The task is run inside a try/finally to start the transaction before the execution and commitOrRollback the transaction after the task, which is an issue when the transaction timeout because the potential underlying error could be swallowed by the transaction timeout exception.

We should improve that by catching the potential underlying exception and adding the transaction timeout as information to it.

Study the possibility to use the TransactionHelper and do the improvement over there.