[optimizer] report per-transform metrics

[mgree]

Adds metrics for per-transform information (how often did the transform fire? how often did it change the AST?); enrich the end-to-end optimization time metric to add log-lines with per-transform timing information, which should aid in debugging.

Designed with advice from @antiguru.

Motivation

• This PR adds a known-desirable feature.
  https://github.com/MaterializeInc/database-issues/issues/8764

Checklist

• This PR has adequate test coverage / QA involvement has been duly considered. (trigger-ci for additional test/nightly runs)
• This PR has an associated up-to-date design doc, is a design doc (template), or is sufficiently small to not require a design.
• If this PR evolves an existing $T ⇔ Proto$T mapping (possibly in a backwards-incompatible way), then it is tagged with a T-proto label.
• If this PR will require changes to cloud orchestration or tests, there is a companion cloud PR to account for those changes that is tagged with the release-blocker label (example).
• If this PR includes major user-facing behavior changes, I have pinged the relevant PM to schedule a changelog post.

[jkosh44]

Adapter changes LGTM

[shepherdlybot]

Mitigations

Completing required mitigations increases Resilience Coverage.

• (Required) Code Review 🔍 Detected
• (Required) Feature Flag
• (Required) Integration Test 🔍 Detected
• (Required) Observability
• (Required) QA Review
• (Required) Run Nightly Tests
• Unit Test

Risk Summary:

The pull request has a high risk score of 80, driven by predictors such as the "Sum Bug Reports Of Files" and "Delta of Executable Lines." Historically, PRs with these predictors are 115% more likely to cause a bug compared to the repository baseline. Although the observed and predicted bug trends in the repository are both decreasing, the presence of one file hotspot suggests a need for careful review.

Note: The risk score is not based on semantic analysis but on historical predictors of bug occurrence in the repository. The attributes above were deemed the strongest predictors based on that history. Predictors and the score may change as the PR evolves in code, time, and review activity.

Bug Hotspots:
What's This?

File	Percentile
../src/coord.rs	100