Clarify REST query parameters for accounts search

[fabrice102]

Summary

The role of the query parameters application-id and asset-id may be unclear in the endpoint /v2/accounts. I think it would be great to clarify the following:

• do the results include creator or opt-in or both accounts?
• for assets, do the results include non-opt-in managers (managers may manage an asset within being opt-in).
• for deleted assets and apps, do the results include former creators? does it include still opt-in accounts? does it include managers? (assets and apps can be deleted while accounts are still opt in)

Scope/Requirements

Documentation update in https://github.com/algorand/indexer/blob/develop/api/indexer.oas2.json#L82