Clarify labels for user inputs and link dangling labels

[m158261]

References

Meaningful labels are provided when user input is required. (WCAG Criteria 1.1.1 (A))). Text issue area # 6 in #9399

This is a more up to date implementation of #14987

Code changes

Placeholders and aria-labels have been added to input areas to provide greater screen reader accessibility.

User-facing changes

Placeholder text will now be more descriptive in input fields. Aria-labels have been added to some input fields to improve accessibility.

Backwards-incompatible changes

None

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[m158261]

Hey @krassowski, I'm having some trouble with failing integrity. I've run jlpm run integrity and pushed the results. Is there something I'm missing? Thanks in advance.

[m158261]

Hey @krassowski, @gabalafou. I've made the changes requested in #14987. Please let me know if any further changes are required. Thanks in advance.

[m158261]

Hey @krassowski, I've had a bit of trouble with merge conflicts. I've fixed it and will update the snapshots after the pipeline has completed.

[m158261]

Please update galata snapshots

[github-actions]

Galata snapshots updated.

[m158261]

Hey @krassowski, I don't think the test failures are related to my code changes. Are there any further changes required for this PR?

Thanks in advance.

[tonyfast]

@m158261 the user facing changes make sense. great stuff!

[krassowski]

Thanks for the ping. Check Release and Pull Request Labeler failures are unrelated (tracked in #15462 and #15488 respectively) but the visual regression failures are as the only two failures for the main job are for modified snapshots:

    [jupyterlab] › test/jupyterlab/notebook-toolbar.test.ts:54:7 › Notebook Toolbar › Paste cell ───
    [jupyterlab] › test/jupyterlab/sidebars.test.ts:31:9 › Sidebars › Open Sidebar tab extensionmanager.main-view 

and there are additional failures in documentation which are due to the need to update the extension manager snapshots there.

Let's summon the bot: please update snapshots

[github-actions]

Documentation snapshots updated.

[github-actions]

Galata snapshots updated.

[krassowski]

Thanks @m158261. Good to go if all green.