Only show available endpoints in Swagger

[jasny]

If a service, like identity indexing, is disabled, the endpoints for that controller should not be shown in Swagger.

This can be done by explicitly including modules (https://docs.nestjs.com/openapi/introduction#document-options). But maybe there's a better option.

[sbrekelmans]

Will the api remain active? Maybe it's more clear to keep the api in swagger, but to return a message or error stating indexing for service x is disabled on the node.

If a service depends on the api, and the indexing is switched off for some reason, the service won't be able to tell the difference between (for example) a hash not being found or just removed from the index. An error message that states the indexing is turned off would be better I think.

[jasny]

The indexer doesn't necessarily index everything. If it only indexes anchors from your trust network, it give a 404 if the hash was anchored by an address outside your trust network. It up to you to properly configure the service to match your use case.