Fixes for a1b64e, ebe86a due to surveys

[tombrunet]

Adds an example for a modal that 'traps' the keyboard, but can be dismissed by standard navigation and therefore allows an escape.

Closes issue(s):

• closes Focusable element has no keyboard trap via standard navigation - Expectation + add clarification #1909

Need for Call for Review:
This will require a 2 weeks Call for Review << new rule, or substantial changes affecting a large number of test cases, if in doubt, use this. >>

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