The rules require comparing if tiles are equal, which used to be a string comparison as we just
converted the image to a path. With ImageData this doesn't
work anymore, so this patch proposes an optional path
property that makes the code also a tad bit more readable.
Share tsconfig.json so that ava runs the typescript compiler also on the tests.
Similary, the syntax check now also covers the tests.
Sadly, the exception that the Slint compiler throws is not type declared,
so we have to use any.
Similarly, the object share returned by loadFile() is unknown
in terms of properties, callbacks, etc.
