refactor: Remove deprecated property window from dart:ui in favor of PlatformDispatcher

[Nidal-Bakir]

New Pull Request Checklist

• I am not disclosing a vulnerability.
• I am creating this PR in reference to an issue.

Issue Description

Closes: #877

Approach

Use the PlatformDispatcher class as recommended by the Flutter docs see window class docs

TODOs before merging

• Add tests
• Add changes to documentation (guides, repository pages, in-code descriptions)
• A changelog entry

[parse-github-assistant]

Thanks for opening this pull request!

• 🎉 We are excited about your hands-on contribution!

[codecov]

Codecov Report

Patch coverage: 50.00% and project coverage change: -0.02 ⚠️

Comparison is base (518f768) 38.69% compared to head (1e982e9) 38.68%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #878      +/-   ##
==========================================
- Coverage   38.69%   38.68%   -0.02%     
==========================================
  Files          56       56              
  Lines        3277     3278       +1     
==========================================
  Hits         1268     1268              
- Misses       2009     2010       +1     

Impacted Files	Coverage Δ
packages/flutter/lib/parse_server_sdk_flutter.dart	8.62% <50.00%> (-0.16%)	⬇️

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[mtrezza]

Is this a breaking change or only an internal refactor without any effects for developers?

[Nidal-Bakir]

Internal refactor the developers will not notice it

[mtrezza]

Alright, so we also don't need a changelog entry for it. All looks green - yay! - can we merge this?

[Nidal-Bakir]

sure, we can!!!!!!!! finally :)

[mtrezza]

Is this the last breaking change for the Parse Flutter SDK? If so, we could release Flutter 5.0.0 with this PR.

• Why do we need feat: Upgrade parse_server_sdk to 5.x.x #868 if all checks are green in this PR already? That would be another breaking change we'd probably have to include before a Flutter 5 release.
• The Dart SDK has a version constant const String keySdkVersion = '5.0.0'; in parse_constants.dart that needs to be kept in sync manually with the version in pubspec.yaml. Does the Flutter SDK have something similar?

[Nidal-Bakir]

Why do we need #868 if all checks are green in this PR already? That would be another breaking change we'd probably have to include before a Flutter 5 release.

But then if anyone uses Flutter SDK will be locked to Dart SDK 4.x.x.
And will not see any updates on the Dart SDK. because the Flutter SDK constraint it to <5.0.0

The Dart SDK has a version constant const String keySdkVersion = '5.0.0'; in parse_constants.dart that needs to be kept in sync manually with the version in pubspec.yaml. Does the Flutter SDK have something similar?

No, there is nothing like that in the Flutter SDK

[mtrezza]

Alright, I'll go ahead and merge.