Improve Pagination Types

[jherdman]

Description

The previous iteration of these type was accounting for the generated page numbers being either a string (SEPARATOR) or numbers.

In this commit I introduce a much narrower type for the getPageItemsToDisplay function. In doing so we more closely map to the reality of the implementation and can use a more appropriately narrow type for onSelectPage.

This resolves some challenges with ECO.

Changes include

• [x] breaking change: a change that is not backwards-compatible and/or changes current functionality
• [x] fix: a non-breaking change that solves an issue
• [ ] feature: a non-breaking change that adds functionality
• [x] chore: contains no changes affecting the library, such as documentation or test updates

Feature checklist

• [ ] Appropriate tests have been added
• [ ] Documentation has been updated
• [ ] Accessibility has been considered

[github-actions[bot]]

:tada: This PR is included in version 10.2.6 :tada:

The release is available on:

• GitHub release
• npm package (@latest dist-tag)

Your semantic-release bot :package::rocket: