Python iterable multiports

[Soroosh129]

This makes multiports in the Python target iterable, which makes accessing them more Pythonic.

For example, previously, a multiport could only be iterated on as:

for i in range(len(multiport)):
    print(multiport[i].value)

Now, you could iterate over each port directly:

for port in multiport:
    print(port.value)

[lhstrh]

This is a nice improvement!

[cmnrd]

Great idea! Should we merge this?