Use the new WebKit content filters API for the adblocker
There's a few things missing and currently after I have just rebased today on top of
master saving the sidecar files is failing; so the JSON rule set files are always downloaded. I'll be ironing out the rough edges in the next days but I think this is more or less ready for initial feedback.
Needs WebKitGTK+ built with the patches for the following two WebKit bugs:
- #193622 - [GTK][WPE] Add content extensions support in WKTR and unskip layout tests.
- #167941 - [WPE][GTK] Enable support for CONTENT_EXTENSIONS.
You will need to change the URLs for the adblocker rule sets to make them point to a JSON-formatted resource. For example:
gsettings set org.gnome.Epiphany adblock-filters "['https://better.fyi/blockerList.json']"