rewrite: ext.pages

[OmLanke]

Summary

Rewrite of ext.pages for cleaner and more modular code. Original Repo

Using ext.paginator namespace to avoid breaking changes at ext.pages (suggestions welcome!)

I'll try to update this PR comment with more details

Information

• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed).
• This PR is not a code change (e.g. documentation, README, typehinting,
  examples, ...).

Checklist

• I have searched the open pull requests for duplicates.
• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• If type: ignore comments were used, a comment is also left explaining why.
• I have updated the changelog to include these changes.