Evaluate FB `asciiOptimization: true` with latest Dart/Flutter

[vaind]

See TODOs in code_chunks.dart #349 (comment)_

The Dart SDK issue is resolved now by https://dart-review.googlesource.com/c/sdk/+/221467 - after it's part of the released SDK, check the influence on benchmarks

[Vahid1919]

asciiOptimization: true performs much better overall. I noticed that the first time I run it with asciiOptimization: true, the readAll takes about 8 ms and then decreases with each run until it stabilises around 6ms after I run it multiple times.
With asciiOptimization: false it is more random and stays between 7-9ms.

Tested on Flutter 3.0.1 & Dart 2.17.1

[greenrobot-team]

Updated TODOs, closing this then.