Need a way to put a device agent in developer mode into SAFE_MODE

### Description

**As a** Developer
**I want to** start the device agent NR instance in safe mode
**so that** I can recover from bad flow edits

If developing on a device and make a change that breaks the flow it's impossible to fix the flow.

If there was a way to push the `NODE_RED_ENABLE_SAFE_MODE=true` environment variable

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate