logging: support log collection from external smeshers

[dshulyak]

We are missing important information that are required to troubleshoot concurrency-related issues. For instance in devnet220 in layer 8345 there are 2 proposals that are created with old base ballots and without votes for recent layers. It indicates that the hare didn't complete on those smeshers, while the rest of the cluster completed hare successfully.

There are two options:

1. Integrate https://github.com/elastic/beats/tree/main/libbeat into spacemesh binary
2. Integrate https://github.com/elastic/beats/tree/main/filebeat as a daemon, and manage that daemon from smapp

I prefer to go with 1st option

[dshulyak]

With loki there is simpler version of the client . it needs to be integrated as a WriteSyncer to zap.Core . The client itself batches log entries in the background and instrumented with relevant metrics, so that we will know if logger will use a lot of traffic.