Write developer-centric flows of "how ocean works" (do for v4)

[alexcos20]

Target audience: developers

• cover publish flows
• cover pricing schema flows
• cover consume flows
• cover c2d

Flows should highlight the flow of info between market -> ocean.js -> aqua / provider , subgraph, etc

It could have UML sequence diagrams.

[LoznianuAnamaria]

Done in Docs V2.