Module API: Expose clock to get current time

[MadLittleMods]

Currently, you have to access a private field self.module_api._clock.time_msec() to get the current time when writing a Synapse module. Since accessing underscore private fields is frowned upon, we should have an official pattern for this.

Workaround

I suppose the workaround here is to use the time library but it seems a bit sketchy to use a different time than what Synapse is using (flawed comparisons).

import time

now_ts = int(time.time() * 1000))