Right now, when during generation of DRI dokka encounters UnresolvedType it puts there reference to type constructor with empty name. This is unacceptable. The three acceptable strategies of handling that are:

• to crash entire generation process with exception
• to skip generation of documentable for any elements that have unresolvable symbols in their DRIs and emit warnings
• to provide approximation of type constructor fq-name by just using name that failed resolution. In the future we can refine this approximation by using information from import list of enclosing source file.

The goal of this task is to implement those strategies and provide configuration option to switch between them. First option should be the default one.