fix(ui): add role="list" to QList (fix: #17439)

[Evertvdw]

I also added some tests for the QList component. The QItem role="listitem" should be similarly conditional when using li as a tag, because then the listitem role is not necessary. But that could be a next PR.

What kind of change does this PR introduce?

• Bugfix
• Feature
• Documentation
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change?

• Yes
• No

The PR fulfills these requirements:

• It's submitted to the dev branch (or v[X] branch)
• When resolving a specific issue, it's referenced in the PR's title (e.g. fix: #xxx[,#xxx], where "xxx" is the issue number)
• It's been tested on a Cordova (iOS, Android) app
• It's been tested on an Electron app
• Any necessary documentation has been added or updated in the docs or explained in the PR's description.

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature (to avoid wasting your time, it's best to start a new feature discussion first and wait for approval before working on it)

Other information:

[github-actions]

UI Tests Results

    1 files     98 suites   38s ⏱️
1 031 tests 1 031 ✅ 0 💤 0 ❌
1 050 runs  1 050 ✅ 0 💤 0 ❌

Results for commit db8e1ca.

♻️ This comment has been updated with latest results.

[yusufkandemir]

Looks good, nicely done. I have some small suggestions.

[yusufkandemir]

Thanks for contributing, will be available in the next quasar release.