Save clock instructions and add runviewer parser for DummyPseudoclock

[rpanderson]

This PR permits whole-suite works-out-of-the-box changes by adding a runviewer parser to DummyPseudoclock (resolves #52).

The additions to the generate_code method of DummyPseudoclock and the get_traces method of DummyPseudoclockParser mock labscript_devices.PineBlaster, which appeared to be the simplest non-dummy pseudoclock device to mimic the instruction set and runviewer parser of.

[rpanderson]

These changes can be tested in conjunction with #53 using the following experiment script, which is a slightly extended version of that in labscript-suite/labscript-utils#54. Load this into runmanager and submit it to blacs (check 'Run shot(s)') and/or runviewer (check 'View shot(s)').

from labscript import start, stop, add_time_marker, AnalogOut, DigitalOut
from labscript_devices.DummyPseudoclock.labscript_devices import DummyPseudoclock
from labscript_devices.DummyIntermediateDevice import DummyIntermediateDevice

# Use a virtual, or 'dummy', device for the psuedoclock
DummyPseudoclock(name='pseudoclock')

# An output of this DummyPseudoclock is its 'clockline' attribute, which we use
# to trigger children devices
DummyIntermediateDevice(name='intermediate_device', parent_device=pseudoclock.clockline)

# Create an AnalogOut child of the DummyIntermediateDevice
AnalogOut(name='analog_out', parent_device=intermediate_device, connection='ao0')

# Create a DigitalOut child of the DummyIntermediateDevice
DigitalOut(
    name='digital_out', parent_device=intermediate_device, connection='port0/line0'
)

# Begin issuing labscript primitives
# A timing variable t is used for convenience
# start() elicits the commencement of the shot
t = 0
add_time_marker(t, "Start", verbose=True)
start()

# Wait for 1 second with all devices in their default state
t += 1

# Change the state of digital_out, and denote this using a time marker
add_time_marker(t, "Toggle digital_out (high)", verbose=True)
digital_out.go_high(t)

# Wait for 0.5 seconds
t += 0.5

# Ramp analog_out from 0.0 V to 1.0 V over 0.25 s with a 1 kS/s sample rate
t += analog_out.ramp(t=t, initial=0.0, final=1.0, duration=0.25, samplerate=1e3)

# Change the state of digital_out, and denote this using a time marker
add_time_marker(t, "Toggle digital_out (low)", verbose=True)
digital_out.go_low(t)

# Wait for 0.5 seconds
t += 0.5

# Stop the experiment shot with stop()
stop(t)

[rpanderson]

This mimics the structure of labscript_devices.PineBlaster but could/should probably be extracted from connection table properties.

[philipstarkey]

@rpanderson I've implemented the changes I suggested. Happy to merge this one before 3.0.0 release

[rpanderson]

Great! Thanks, @philipstarkey.