Migrate to alternative web view control

Currently, Omea relies on the Internet Explorer engine (e.g. to show the blog posts and whatnot): the only possible solution in the days it was developed, but no longer an acceptable one.

We should migrate to some embeddable Chromium variant instead — and make sure it's properly sandboxed.

Start by locating where Omea currently uses the Internet Explorer engine to display blog posts and other content. Evaluate an embeddable Chromium alternative and its sandboxing requirements; done means the existing web views use the new control and are properly sandboxed.

Written by the indexing model from the issue text.