Enable Connection to NGINX One Console

[mpstefan]

As an NGINX Plus user of NGF
I want my NGF fleet management telemetry to be sent to the NGINX One Console or NIM
So that I can include my NGF installations in my fleet management view in the NGINX One Console
And so that I can later see Observability metrics as soon as possible with minimal setup.

Acceptance

• When preconditions are met for Agent to send data to a management plane, fleet management telemetry will be sent to the URL specified by the user (N1C or NIM) or if none is specified, N1C by default.
• (Does the NGINX Plus JWT cover auth for this?)
• (Do we want to enable this by default if so?)
• A mechanism exists to disable sending any telemetry to a management plane and is documented.
• NGF-specific labels are appended to the telemetry data (via Agent) before it is sent.

Dev Notes

• We shouldn't need to check for OSS if the user has a valid auth to send data.