Add "Other..." option for checkbox & list questions

[WilliamVenner]

This PR adds a feature to checkbox and list questions which allows users to enter custom input. Just need to set other=True when creating the question.

Screen.Recording.2022-10-03.at.15.34.32.mov

[Cube707]

I like the idea and it makes sense as an opt-in feature so that developters an enable it where needed. I will review the code later...

I would argue that its better placed as the last element in the list rather than the first thought. Makes more sense to me.

[cpiemontese]

A little bump to know if this has been reviewed yet 🙏

It would be a very useful feature

[staticdev]

Thanks a lot for the feature, I just made a small comment, it is not mandatory but I would prefer to not have the dots.

[Cube707]

made some small comments.

And the tests fail, I don't have the time to check why at the moment though, maybe you can figure it out quicker than i can

[staticdev]

Last commit broke the tests. I pointed in comment why.

[WilliamVenner]

Cheers all, have made the requested changes. Sorry if the tests still don't pass, I would run them locally but it's a bit of a PITA due to M1 chip. Fingers crossed 🤞🏻