Add the ability to deploy a remotecfg block

[petewall]

This would enable the alloy instances deployed by the chart to be interoperable with the fleet management work.

[petewall]

There can only be one remotecfg, so add something like this inside each alloy instance block:

  remoteConfig:
    url: ""
    auth:
      type: "basic"
      username: ""
      password: ""
    id: <cluster-name>-<namespace>-<pod-name>
    pollFreq: 60s
    attributes:
      platform: kubernetes
      workloadType: statefulset

[petewall]

https://grafana.com/docs/alloy/next/reference/config-blocks/remotecfg/