Add counts sentiment ratio metrics

[volynvlad]

Changes

• Add sentiment ratio metrics for
  • 4chan
  • reddit
  • telegram
  • twitter
  • total
    sources

Ticket

Checklist:

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have tried to find clearer solution before commenting hard-to-understand parts of code
• I have added tests that prove my fix is effective or that my feature works

[IvanIvanoff]

balance and volume consumed (now named weighted) are already in master.
Closing this PR. The docs_count and ratio metric can be added with a new PR later.