Bulk Transfers: Refactoring prepare, position, fulfil handlers to support bulk transfers messages

[elnyry-sam-k]

Goal:

As a Hub Operator
I want to implement the /bulkTransfers end-point
so that I can support the bulk Transfers use-case (based on the API Definition).

This specific story is for refactoring existing handlers - prepare, position and fulfil to support bulk transfers related messages and handle them as relevant (following Sequence diagrams, designs)

Tasks:

• Update implementation for
  • prepare handler (golden path) [@ggrg]
  • position handler (golden path) [@ggrg]
  • fulfil handler
• Automated Tests
• Sequence diagrams or markdown files updated if issues identified during implementation [@ggrg]

Acceptance Criteria:

• prepare handler is refactored to support bulk transfers (golden path)
• position handler is refactored to support bulk transfers (golden path)
• fulfil handler is refactored to support bulk transfers (golden path)

Pull Requests:

• Feature/747-748 Bulk Processing Handler and existing transfer handlers central-ledger#289
• Feature/Bulk Transfers POC - Bulk prepare ml-api-adapter#116
• Feature/746-748-747 Implement Bulk Transfer Fulfil central-ledger#290

Follow-up:

• TBD

Dependencies:

• Bulk Transfers: Review initial DB design, Draft values for actions, types in messages for bulk #744
• Bulk Transfers: Implement bulk-prepare handler #745
• Bulk Transfers: Implement bulk-fulfil handler #746

Accountability:

• Owner:
• QA/Review: DA