Allow App Builder application logs to be forwarded to New Relic.

### Expected Behaviour

Allow App Builder application logs to be forwarded to New Relic.

Customer Quote:
```
I would love to have app builder log management being able to forward to New Relic Logs as well. Or even just anything that NR Logs supports like fluentd.
```

### Actual Behaviour

Currently only Splunk Cloud, Splunk Enterprise, and Azure Log Analytics are supported.
See: `aio app config set log-forwarding`

### Reproduce Scenario (including but not limited to)
N/A

#### Steps to Reproduce

N/A

#### Platform and Version
N/A

#### Sample Code that illustrates the problem
N/A

#### Logs taken while reproducing problem
N/A