Support task logging

[ryankurte]

• For development it'd be super neat to be able to throw a task at a device, then stream the logs back to your local terminal.
• For production it'd be useful to write logs to a file (or a few files in rotation) that could be grabbed from the file system and viewed for debugging purposes.

Tasks

• [ ] Propagate task context through log calls (requires #4)
• [ ] Add log handle(s?) to WasmTask_t object
• [ ] Create log manager to control log rotation etc.
• [ ] Add logging config to task commands