Focus on the Handsontable instance within the iframe won't persist for clicking outside the iframe

[wszymanski]

Context

There was a need to add an extra HOT's unlisten call.

How has this been tested?

Tested on pages containing iframes.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature or improvement (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Additional language file or change to the existing one (translations)

Related issue(s):

1. https://github.com/handsontable/dev-handsontable/issues/1643

Affected project(s):

• handsontable
• @handsontable/angular
• @handsontable/react
• @handsontable/vue
• @handsontable/vue3

Checklist:

• I have reviewed the guidelines about Contributing to Handsontable and I confirm that my code follows the code style of this project.
• My change requires a change to the documentation.

[github-actions]

Launch the local version of documentation by running:

npm run docs:review 5fd0dd15a81b798124ad4919335cd418c2472f4f

[juan-rvty]

Hi, I believe this might be related to: #11015