feat(merchant_account): add merchant account list endpoint

[Narayanbhat166]

Type of Change

• New feature

Description

This will add the support for querying merchant accounts with a filter. Can be used by dependant crates

Additional Changes

• This PR modifies the API contract
• This PR modifies the database schema
• This PR modifies application configuration/environment variables

Motivation and Context

To allow list merchant accounts

How did you test it?

• Create a merchant account - Note the org_id.
• Call list merchant account with the above noted org_id

curl --location 'http://localhost:8080/accounts/list?organization_id=org_abcdefghijklmn' \
--header 'Content-Type: application/json' \
--header 'Accept: application/json' \
--header 'api-key: test_admin' \
--data ''

Postman test results

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code