Fix a problem with keyboard navigation and scrolling on window-scrolled instances.

[jansiegel]

Context

The problem described in handsontable/dev-handsontable#49 is most probably caused by a fix made for #3070.
However, that fix seems to be no longer working (the drag-to-scroll feature for window-scrolled instances does not work currently).

This PR aims to:

• Fix handsontable/dev-handsontable#49
• Make the "drag to scroll" functionality work for both element-scrolled and window-scrolled instances (so, in a while, re-fix Table scrolling bug when scrollable element is window #3070)

How has this been tested?

• Tested manually
• Added test cases for element-scrolled instances

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#49
2. Table scrolling bug when scrollable element is window #3070

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.

[jansiegel]

Note for the reviewer:
I couldn't figure out how to test drag-to-scroll on a window-scrolled instance (the problem is simulating mouse movement outside of the window), so I added just the tests for the element-scrolled ones. If you have any ideas on how to test those, I'll gladly add them.

[budnix]

Can I ask to update the types as well? https://github.com/handsontable/handsontable/blob/feature/dev-issue-49/handsontable/types/plugins/dragToScroll/dragToScroll.d.ts#L12

[budnix]

.. and then it'd be nice to create a test case for this plugin covering all TS things. Something like this https://github.com/handsontable/handsontable/blob/feature/issue-10515/handsontable/src/plugins/customBorders/__tests__/customBorders.types.ts

[github-actions]

Launch the local version of documentation by running:

npm run docs:review 9eec2888d369fdcc1d5a11b54f4ab14ec4879bc1