Add moar counters

[seanstory]

Problem Description

We don't count too many things in the framework. It would be good to start counting a lot more things.

Proposed Solution

I suggest counters like:

• requests made to the 3rd party
  • total
  • average latency
  • max latency
  • response codes totals
• requests made to Elasticsearch
  • total
  • average latency
  • max latency
• documents seen
• documents filtered by basic sync rules
• documents errored during elasticsearch _bulk
• documents downloaded
• documents transformed by extraction service
• documents rejected by extraction service
• average document processing time
• max document processing time
• time till first document etc

[artem-shelkovnikov]

Should this ticket be closed? @seanstory

[seanstory]

I'd left it open because we didn't add counters for all the things we really should be counting - I'd just changed in https://github.com/elastic/connectors/pull/2347 how we print out what we were already counting.

I've edited this issue's name and description to make clear that this is just about counting more things.