Transfer more tests to shared test project

[kuhnroyal]

This PR transfers some download and header/options tests to the shared test project and thus enabled them for the Http2 adapter.

New Pull Request Checklist

• I have read the Documentation
• I have searched for a similar pull request in the project and found none
• I have updated this branch with the latest main branch to avoid conflicts (via merge from master or rebase)
• I have added the required tests to prove the fix/feature I'm adding
• I have updated the documentation (if necessary)
• I have run the tests without failures
• I have updated the CHANGELOG.md in the corresponding package

Additional context and info (if any)

[github-actions]

Code Coverage Report

Package	Base Coverage	New Coverage	Difference
dio	🟢 80.26%	🟢 81.1%	🟢 0.84%
Overall Coverage	🟢 80.26%	🟢 81.1%	🟢 0.84%

Minimum allowed coverage is 0%, this run produced 81.1%

[AlexV525]

https://github.com/cfug/dio/actions/runs/8513054967/job/23315952339#step:15:121

[dio]: ::group::❌ loading test/test_suite_test.dart (failed)
[dio]: Failed to load "test/test_suite_test.dart":
[dio]: ../../../../.pub-cache/git/dio-1c2843a2fab1c3795272df1e81502616761e192e/dio_test/lib/src/test/upload_tests.dart:66:20: Error: No named parameter with the name 'exclusive'.
[dio]:       f.createSync(exclusive: false);
[dio]:                    ^^^^^^^^^
[dio]: ../../../../.pub-cache/git/dio-1c2843a2fab1c3795272df1e81502616761e192e/dio_test/lib/src/test/upload_tests.dart:95:20: Error: No named parameter with the name 'exclusive'.
[dio]:       f.createSync(exclusive: false);
[dio]:                    ^^^^^^^^^

[kuhnroyal]

I think this is happening due to the git dependency.

[kuhnroyal]

This likely happens on the min SDK because we have to use an old melos version there which seems to no create the overrides correctly.

[AlexV525]

We can also remove the exclusive since it defaults to false.

[kuhnroyal]

Yea but that doesn't really fix the issue, only the current symptom.

Something else is wrong here, I played around in kuhnroyal#28 and the stable workflow failed with analyzer errors that I have fixed in the same PR. Like it is analyzing an older dio version. Not sure.

In any case, the http package is doing using a similar approach and they have their test package in the main pubspec as path dependency: https://github.com/dart-lang/http/blob/master/pkgs/http/pubspec.yaml
I think that's what we need to go back.