Deliver and integration of Transactions + Sankey Diagram for WB PoC

[diminator]

Provide backend and frontend state store

• Index celo and provide graphql endpoint [WB, Grameen]
• Read Transactions from Celo network [WB, Grameen]
  (Transactions list and detail endpoint, assume filter/project addresses are known)
• Prepare data to populate sankey diagram [WB, Grameen]

Create frontend components

• Sankey diagram [WB, Grameen]
• List & detail view on transactions [WB, Grameen]
• Filter and search component [WB, Grameen]
• Hover view on sankey [WB, Grameen]
• Create Transaction [defer to mocks for WB, not for Grameen]