Handle encountering unsupported quantum intrinsics

[nilslice]

In some QIR, there may be intrinsics or other elements that we have not added support for or cannot support. We should consider that another stage in compilation might support these and can thus offer a configurable way to adapt.

Configurability could be in the form of:

1. Exit with a failure when something unsupported is encountered (default ?, leaves unsupported elements in place)
2. Check if a flag is set to continue on error (e.g. --allow-unsupported)
3. more?