Search modal - Missing modal trap

[umbrabot]

Steps to replicate:

1. Open search modal in the top navigation (top right)
2. Modal will appear (modal is missing modal trap)

Issue: Modal dialogs: Users must not be able to Tab away from a modal dialog without explicitly dismissing it

Why it matters: The purpose of a modal dialog is to constrain user input (temporarily) to controls within the dialog. Just as mouse users should not be able to click elements outside the dialog, keyboard users should not be able to Tab to elements outside the dialog.

How to fix:

• If a modal dialog contains a single focusable element (such as an 'OK' button), simply prevent any behaviour from occurring when the user presses the Tab key.
• If a modal dialog contains multiple focusable elements, force focus to cycle through those elements until the dialog is dismissed by the user.

W3 reference: https://www.w3.org/WAI/WCAG21/Understanding/focus-order.html

[mikecp]

Setting to Done after merge of PR #12786

[nul800sebastiaan]

Fixed in https://github.com/umbraco/Umbraco-CMS/pull/12786