* disabled several entirely
* fixed some easy ones

In most cases, we now just use the new (C# 12.0) collection expression syntax. However, we've disabled IDE0305 because it makes suggestions that aren't an obvious improvement. It wants to rewrite use of ToArray() to be a collection expression. E.g. something.ToArray() would become [.. something]. Perhaps that will seem natural once we've all got used to spreads in collection expressions, but to me (idg10) today that looks odd.

Make UWP test runner use the same warning settings as everything else, except for CS0618, which a large number of tests appear to depend on.