Update Material tokens to v0.81. by @darrenaustin in https://github.com/flutter/flutter/pull/98149

Add keyLog and connectionFactory to HttpClient implementations by @brianquinlan in https://github.com/flutter/flutter/pull/98045

Reland “[EditableText] honor the “brieflyShowPassword” system setting #97769 “ by @LongCatIsLooong in https://github.com/flutter/flutter/pull/98150

[performance] Process dirty nodes from top to bottom during paint to avoid unnecessary layer tree walks by @goderbauer in https://github.com/flutter/flutter/pull/98219

Refactor TextSelectionOverlay by @chunhtai in https://github.com/flutter/flutter/pull/98153