dsm-api: throw if ioService thread calls blocking dsm-api routine

ioService thread is event loop. Bad things happen when event loop is blocked.

model/Status is the first class that uses ioService event loop to call methods into dsm-api. And it is calling broadcast methods that do not block.

So it this commit shall not cause regressions.

Depends on ds485-stack/dsm-api!59 (merged)