Remove mentions to nitrogen

### What happened?

1. Nitrogen is being mentioned in some parts of the SDK, it is an old/internal name for the microgrid service.

### What did you expect instead?

Mentions to "nitrogen" should be replaced by "microgrid service" or similar.

### Affected version(s)

_No response_

### Affected part(s)

Documentation (part:docs)

### Extra information

_No response_