Limit work in progress labels to 80 characters when the width of the console is not known (e.g. when running under Mintty or from the tooling API), to make wrapping less likely. Wrapping of the labels currently doesn't work particularly well on some consoles. Also generate less garbage on each 'update now' console event.
Rework `BlockingHttpServer` API to separate expected HTTP request from the action that should be performed when the request is received. Also remove usages of `HttpExchange` from tests (but not fixtures) as this is an internal detail of the fixture.