Feat/perf testing

[GAlexIHU]

Overview

Adds comparative performance tests for using projections versus materialized views & for baselining raw query execution compared to OpenMeter performance.

Based on the results projections have around 2-3x worse performance compared to using materialized views. The sample tests were run on 1M events with the default configuration in perf/configs.
Sample screenshots of the test runs:

(see MATERIALISED & PROJECTION lines)

(see CLICKHOUSE & OPENMETER lines)

For running the tests for yourself check docs/perftest.md and perf/k6/README.md

Fixes #700

Notes for reviewer

Still in draft as the dagger automation for perf tests currently hangs.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes