port file-service to use indexer-framework

[hopeyen]

Description

Port subfile server to indexer service framework
acceptance:

• config files instead of args ✅ 2024-02-09
• implement service traits ✅ 2024-02-09
• move routes ✅ 2024-02-09
• update namespaces; update request and response structure ✅ 2024-02-09
• update corresponding download clients: routes and namespaces in request, request parsing ✅ 2024-02-09
• ensure service can receive free query or paid query
  • paid validity wait til confirmation of TAP full testing) ✅ 2024-02-09
• update e2e tests

Issue link (if applicable)

resolve #30

later use graphql_client for response types: #38

Checklist

• Are tests up-to-date with the new changes?
• Are docs up-to-date with the new changes? (Open PR on docs repo if necessary)