[DX-1040] Add p99 metric to BenchSpy

[Tofel]

---

Below is a summarization created by an LLM (gpt-4-0125-preview). Be mindful of hallucinations and verify accuracy.

Why

The changes introduce the 99th percentile latency metric (p99 latency) across various files in the BenchSpy documentation and implementation. This addition allows users to measure and compare the latency at the 99th percentile, providing a more comprehensive understanding of the performance characteristics and potential bottlenecks in their systems.

What

• book/src/libs/wasp/benchspy/loki_std.md, real_world.md, reports/standard_report.md, simplest_metrics.md
  • Added p99 latency metric to documentation, highlighting its inclusion in performance metrics.
• wasp/.changeset/v1.51.1.md
  • Documented the addition of p99 metric to BenchSpy's Direct and Loki standard Query Executors.
• wasp/benchspy/direct.go, direct_test.go, loki.go, report.go, report_test.go, types.go
  • Implemented p99 latency metric in Direct and Loki Query Executors and their tests.
  • Updated comparison and validation functions to include p99 latency.
• wasp/examples/benchspy/direct_query_executor/direct_query_executor_test.go, direct_query_real_case_test.go, loki_query_executor/loki_query_executor_test.go
  • Updated tests to incorporate p99 latency in comparisons and assertions.