update WebView to support gtk 4

[sigmaSd]

The latest WebView update uses webgtkkit 6 and gtk 4 would be great if this library updates to the latest version

[eliassjogreen]

Yeah, webview is in need of some major refactoring and housekeeping. Haven't had the time nor motivation to update it in the last year or so... Help is ofc always welcome :)

[sigmaSd]

The good thing is the new release doesn't seem to have new breaking changes.

I dlopened the new library directly, and it wroked on linux, so it seems like its just a matter of updating the buildscript. (I confirmed its using gtk 4 using GTK_DEBUG=all)

I'm not familiar with cross building for mac and windows, so I can't help in this area for now.

[SteffenL]

I haven't been involved in this project but I'll just say that the core webview library can currently be compiled to support one of the following, but not all at the same time:

• GTK 4, WebKitGTK API 6.0
• GTK 3, WebKitGTK API 4.1
• GTK 3, WebKitGTK API 4.0

Note that some features aren't available anymore in GTK 4 and have no replacements.

[eliassjogreen]

Looking at this now quickly I think the biggest problem is that we are using a 2 year old version of webview. We need to update the build scripts to support the latest webview and then we should be able to build for each variant. We should then probably build all of the different variants in matrix CI action, that way we can support each variant :)

[congzhangzh]

related: #186