Feature: Add address ledger API

[ghost]

Summary

Add an API set that returns a balance ledger for an address.

Problem Definition

Existing services are scraping the Tx API to pull ledger records (fees paid, credits/debits) for an address. It would be nice to give them that data already parsed out, in addition for future use for the UI.

Dependent on #115

Proposal

Using the event log db tables:

• Add a function to collect ledger type records for an address, returning
  • tx timestamp
  • tx hash
  • status (success/failure)
  • fee amount/denom
  • fee payer
  • cumulative balance change (sum of applicable changes where the address is sender or receiver)
  • list of the following object structure
    • tx message type
    • denom
    • credit
    • debit
    • sender
    • receiver
• Add an api at /api/v2/accounts/{address}/ledger to return the above object structure
  • Path param address
  • Query param begin date
  • Query param end date
    • These dates will be used to filter the tx set down
• Given time, might be helpful to allow for a list of addresses vs a single address

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For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned