Add partial repayment API endpoints to the indexer

[Hrom131]

Describe the feature

Describe the feature

Description

In order for the front end to implement partial repayment logic, it must be able to retrieve information about the current debt for an offer and its repayments. For a proper UI, it must also be able to retrieve the repayment history for a specific offer, as well as information about the lender’s claims and the protocol.

Acceptance Criteria:

• Endpoint for retrieving information on all repayments for a specific offer
• Endpoint for retrieving information on vaults for a specific offer
• Endpoint for retrieving all Protocol Fee UTXOs
• Endpoint for retrieving statistics on all protocol fees
• Updated endpoints for retrieving a list of offers.

Dependencies

• Add partial repayment tracking to the indexer #131
• Add lender vaults tracker to the indexer #132
• Add protocol fee vaults tracking to the indexer #133