Dynamic Reload of Configuration

[onelapahead]

What would you like to be added?

The ability for Paladin to dynamically reload its configuration based on changes to config files such as domains and registries. Note that the processes should not restart/crash, but ideally only the impacted internal components are restarted without compromising any in-flight transaction processing or state.

Why is this needed?

This allows for zero-downtime configuration updates in dynamic deployment environments such as cloud-native Kubernetes clusters.

It will allow for less "hacky" Operator code implemented when addressing #397.

[onelapahead]

If we use fsnotify rather than target Linux only and inotfify - we'll want to keep hyperledger/firefly-common#156 in mind. Whether we roll our own fswatcher like lib in Paladin, or re-use firefly-common's.