add transcript with edit.namespace output for base and http

[aryairani]

Overview

A place to notice pretty-printing changes.

Implementation notes

Interesting/controversial decisions

• It takes a while to run, we may want to split them out into a different test that utilizes some codebase caching.
• It produces big output which may clog Github Actions log viewing.
• It doesn't try to round-trip them, as they would both fail.
• It's pinned to specific releases to avoid spurious output changes

Test coverage

Loose ends

Especially the caching thing.

[aryairani]

It adds to the transcript running time (especially with the clone) but I figure it's better to get it in first, so we can spot how changes affect the output, and speed it up later.