Refactor: new project structure

[gusinacio]

• Rename executor to context
• Rename modules:
  • tap_receipt to receipt
  • receipts_aggregate_voucher to rav
  • tap_manager to manager
• Move SignedReceipt from manager to receipt
• Move SignedRAV from manager to rav
• Rename EscrowAdapter to EscrowHandler
• Remove ReceivedReceipt and StoreReceipt
• Rename mock to in_memory context
• Remove serialize from RAVRequest
• Remove ReceiptAuditor and use their methods inside EscrowHandler
• Move checks::mock to memory::checks

[coveralls]

Pull Request Test Coverage Report for Build 8237551665

Details

• 126 of 160 (78.75%) changed or added relevant lines in 9 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.4%) to 79.263%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
tap_core/src/rav/request.rs	0	1	0.0%
tap_core/src/receipt/received_receipt.rs	13	15	86.67%
tap_core/src/receipt/checks.rs	0	3	0.0%
tap_core/src/manager/adapters/escrow.rs	30	36	83.33%
tap_core/src/manager/context/memory.rs	58	80	72.5%

Totals
Change from base Build 8237367878:	-0.4%
Covered Lines:	925
Relevant Lines:	1167

---

💛 - Coveralls

[github-actions]

🤖 Cargo Audit Report 🤖

(Empty means OK! 👍)

[aasseman]

LGTM