CodeQL: Support multiple types for `instanceof`

Currently `instanceof` only supports a single type as right operand. This can make its usage quite verbose when multiple alternative type checks have to be performed. For example search in the CodeQL source with the following Regex (increasing or decreasing the number in `{3,}` to find longer or shorter chains):
```
(.+) instanceof [a-zA-Z]+([\s\n]+or[\s\n]+\1 instanceof [a-zA-Z]+){3,}
```

This finds for example:
- https://github.com/github/codeql/blob/3119885a9b21951aafac88e01c946b3e7cfbe163/java/ql/lib/semmle/code/java/ControlFlowGraph.qll#L441-L451
- https://github.com/github/codeql/blob/3119885a9b21951aafac88e01c946b3e7cfbe163/java/ql/lib/semmle/code/java/JDK.qll#L157-L161

Would it be possible to allow multiple types for the `instanceof` expression? The syntax could be similar to a set literal, also allowing a trailing comma (except that currently a set literal is defined as expression, so it would not be valid for types), for example:
```codeql
this instanceof [PrimitiveType, NullType, VoidType, BoxedType, TypeString]
```