Notion 2025-09-03 API Support (0.7.0)

A new update, mainly adding support for the latest [2025-09-03](https://developers.notion.com/reference/changes-by-version) Notion API release version. With some extra fixes & improvements added in.

🟢 Additions
- Support for the latest API version, 2025-09-03 added.
- Added support for the Url Notion property type.

🟡 Changes
- Json library changed from Simple JSON to Newtonsoft Json provided by the Unity package manager.
- Newtonsoft Json package is now a dependency for the asset to function.
- Progress bar GUI when downloading data now better represents actual progress.
- Corrected GUI popups mentioning “standalone” asset.
- Removed V1 setting from the asset, as there is no real need for it at present.
- Documentation updated with latest changes.

🔴 Fixes
- Fixed the script template for generating Notion Data Assets so they compile correctly when created.
- Fixed setting changes from the settings provider not applying when changed
- Fixed new data assets not being registered with the index when downloading all assets.