Improve subsource planning

[antiguru]

Improve subsource planning by making various parts of the adapter more scalable.

This PR includes changes to:

• The durable transaction implementation to improve updates and validity checks. Updates are more efficient by cloning less and passing references where possible. Validity checks are more efficient by converting some that assert on name equality to a $n\cdot\log n$, where it previously was $n^2$.
• Planning subsources is more efficient by allocating all IDs in one operation rather than one-by-one.
• Avoiding computing trace data in the storage client when the level isn't high enough.

Takes planning 10k subsources from I-terminated-it-after-one-hour to around one minute.

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.

[ParkMyCar]

Nice! LGTM!

[ParkMyCar]

If you don't mind kicking off a round of Nightlies, it would be much appreciated!

[antiguru]

Nightly in https://buildkite.com/materialize/nightly/builds/11470, but I couldn't trigger it through our tool for whatever reason.