Single-process & single-replica graph + storage daemon

[SuperYoko]

Is your feature request related to a problem? Please describe.
requirement： single process version nebula (storage + graph) use direct function call instead of rpc.

Describe the solution you'd like

1. Integrate graph & storage daemon into one process
2. call storage with direct function call.

Describe alternatives you've considered

Additional context
Add any other context or screenshots about the feature request here.