check all submodules for service interface

[cedricdcc]

All of the following submodules must have a service interface designed to comply to the service model

submodules to check:

• add service to sema.bench and __main__.py #101
• add service to sema.discovery and __main__.py #100
• add service to sema.harvest and __main__.py #99
• add service to sema.query and __main__.py #98
• refactor sema.subyt.main to use service interface #82
• add service to sema.syncfs and __main__.py #102