Enduro/X Core

- If a single transaction branch is managed by tmsrv, it might be committed without journal sync, as result in any way would be committed or aborted.
- If all transactions branches are read_only, also, journal sync is not needed, as non of consistency might be lost.
- Asynchronous commit engine, so that any participant processing in the stage is done asynchronously (i.e. submitted to threadpool & waiting for a response) and then aggregate the results & process. Another option would be to use tpacall() instead of thread pool, for better resource usage.