feature: add diagrams for Data access Layer

[SuccinctPaul]

🌟 Feature Request

• add table description of datebases's tables
• add state-diagram for winness, proof, and scheduler etc tables.

📝 Description

To provide a more clear and concise description of Data access Layer. Better to have the different diagrams of tables and their state transfer. As there are lots of services using the databases.

🤔 Rationale

1. Easier to understand data workflow managed in DAL.
2. Easier to debug.
3. Easier to maintain and add features for guys who wanna leverage the power of zkStack.