Record-by-default creates an AppMap for a function that is run using multiprocessing #201
Description
Currently, a function that's run using the multiprocessing package is instrumented, but there's no way to generate an AppMap for it. This means, for example, that the events property in the AppMap printed by mp/mp.py in #200 (comment) will be empty.
appmap-python should generate multiprocessing recordings automatically, analogous to request recordings. A recording should be started before the function is run, and an AppMap created when it returns.