Add accessible names to profile and notebook dialogs

[acelaya]

After the work from #6187, the has been a second accessibility review, which has highlighted the lack of an accessible name for the notebook dialog.

We have been suggested to use aria-labelledby to do this, which is also the recommendation in https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Roles/dialog_role.

However, since the label value is not displayed anywhere else, this PR implements a solution using aria-label instead.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (0d31f7c) 99.44% compared to head (a3f4802) 99.44%.
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6222   +/-   ##
=======================================
  Coverage   99.44%   99.44%           
=======================================
  Files         266      266           
  Lines       10130    10130           
  Branches     2401     2401           
=======================================
  Hits        10074    10074           
  Misses         56       56           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[robertknight]

Some thoughts:

• Use aria-labelledby only if the content already exists in the UI and just needs to be semantically linked to an element. For assistive-technology only labels, aria-label is more appropriate
• We don't need to include the widget type in labels (eg. "button", "dialog") because that information is already included in the widget's role.
• For these dialogs, we probably do want to make it clear that the dialog belongs to Hypothesis and not the host page. The Hypothesis sidebar iframe for example is labeled as "Hypothesis annotation viewer".