Add key shortcuts and role attributes to the filtering menu's links.

[jansiegel]

Context

This PR:

• Makes the Select All and Clear links react to both Enter and Space keys.
• Adds role=button to those elements.

[skip changelog]

How has this been tested?

Added test cases.

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. handsontable/dev-handsontable#1485

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.
• I have signed the Contributor License Agreement
• My change requires a change to the documentation.

[AMBudnik]

Works perfectly both SPACE and ENTER on those two buttons in 14.0.0 https://jsfiddle.net/mns5rjkz/15/