Discuss the need of access to multiple service instances

[hlxid]

Description

Currently a bundle can have access to only one service instance per service type. We need to discuss if we want to support that a bundle could use multiple instances of a single service type. This is needed if a bundle needs access to e.g. multiple twitch accounts or multiple ftp servers.

References

Todo comment: https://github.com/codeoverflow-org/nodecg-io/blob/a4896b3e881a1a10d807fb9da07c9da161455b48/nodecg-io-core/extension/index.ts#L9