Allow getters to be executed lazily instead of up-front #4234
Description
DAP now allows us to wrap expensive getters in an object and signal that it's to support lazy-fetching of expensive/potential-side-effect properties:
We should look at adopting this and then ditching the option that does this up-front (or keeping it as a way to opt-in to previous behaviour if it's more convenient and you have no concerns about side-effects/perf).
- Roll into Flutter and update its argument classes to pass this value
- Update Dart-Code to support setting this option