feat(dart): make requests abortable

[timonrieger]

allows using the standard http.Client mechanism to abort requests, which is useful for both teardown and overall responsiveness.

port of immich-app/immich#28692

cc @mertalev

Dart: @yissachar
Dart (refactor): @joernahrens
Dart 2: @swipesight
Dart (Jaguar): @jaumard
Dart (Dio): @josh-burton

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[cubic-dev-ai]

1 issue found across 14 files

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[wing328]

thanks for the PR

is this PR backward compatible given the change (above) in method signature?