[FEATURE] Healtcheck endpoint with different metrics

[4TT1L4]

Is your feature request related to a problem? Please describe.
At the moment it is not easy to monitor the performance of the smart order router. The monitoring of the SOR instance is only possible by monitoring the logs and matching regular expressions to extract some information about the inner working.

Describe the solution you'd like
It would be great to have a healthcheck endpoint, that would return different operational metrics.

The SOR would open a port and listen on it for HTTP requests. When a GET request arrives, it would response with a JSON document like the following document:

{
  "started": "2024-02-12 17:01",
  "last-scan": "2024-02-18 14:01",
  "scan-count": 15543,
  "match-count": 154,
  "tx-submitted": 5
}

The JSON structure above is just a proposal. Improvements and changes are welcome.

Describe alternatives you've considered
Alternatives could be to add some prometheus or some other monitoring tool compatible interface

Additional context
The monitoring and observability of the SOR must be improved. This proposal suggest to improve this aspect of the SOR.