[deferred-reexports] Add load-and-evaluation tests

[caiolima]

Covers the "Load and Evaluation" section of #5010 for the deferred re-exports proposal (https://tc39.es/proposal-deferred-reexports/).

This adds 7 scenarios under test/language/export/export-defer/load-and-evaluation:

1. no-consumer-no-load: export defer { x } from dep does not load dep when nothing consumes x.
2. consumer-imports-loads: an import of the deferred binding loads and evaluates its source.
3. chained-defer: a chain of deferred re-exports evaluates every link on the chain when the binding is consumed.
4. reexport-non-defer-consumed: a plain (non-defer) re-export of a deferred binding forces its source to load when the entrypoint consumes it.
5. reexport-non-defer-unconsumed: a plain (non-defer) re-export of a deferred binding forces its source to load even when the entrypoint does not consume it.
6. star-reexport-non-default: export * over a module with a deferred non-default re-export pulls the deferred source.
7. star-reexport-default: export * (ALL-BUT-DEFAULT) skips a deferred default re-export, leaving its source unlinked.

Tests that observe evaluation order populate a shared globalThis.evaluations array from each fixture and assert via assert.compareArray (following previous tests from import-defer). Tests that prove a module is not loaded point at a dependency containing invalid syntax! paired with a positive signal (a marker binding, or evaluation order tracking) to assert that the module was properly executed, but unused optional re-exports were skipped.