Stop using an in-memory slice for counters.

MERGE REQUEST

Overview

Get rid of the in-memory slice to reduce RAM usage.
Add Append functionality.

Example for Visual changes (ie Screenshot)

Issues Closed

Part of #3836

Checklist

Review and complete the checklist to ensure that the MR is complete before assigned to an approver.

• All new methods, or updating methods have clear docstrings
• Testing added or updated for new methods
• Any new packages are added to Makefile and .gitlab-ci.yml
• API documentation updated for API updates
• Module README.md updated for changes to work flow
• Issue added to Sia-UI repo for new supporting features
• Changelog updated