Bug fixes plus compatibility with OpenSesame 4.0

[smathot]

This PR refactors the plugins to be compatible with OpenSesame 4.0. It also fixes in the osscreen class.

[esdalmaijer]

Fab, thanks! I just have two questions:

1. Could you check and clarify the version number? It's listed as 0.8.7 in pygaze/init.py, but as 0.8.0a1 in pyproject.toml. I'm OK to jump to 0.8.0, and imagine the 0.8.7 is a typo?

2. This explicitly switches us from setup.py to poetry for packaging. I still package through the former, so I'm not super keen on deleting the setup files. Is there a need for a switch to poetry, or does it come with some benefit?

[smathot]

Yes sorry it's a bit messy because some of the commits go back a few months. I apparently forgot to submit a PR at the time.

Could you check and clarify the version number? It's listed as 0.8.7 in pygaze/init.py, but as 0.8.0a1 in pyproject.toml. I'm OK to jump to 0.8.0, and imagine the 0.8.7 is a typo?

It should be 0.8.7. I updated pyproject.toml, which I forgot initially.

This explicitly switches us from setup.py to poetry for packaging. I still package through the former, so I'm not super keen on deleting the setup files. Is there a need for a switch to poetry, or does it come with some benefit?

You can have them both if you want. Using pyproject.toml is much easier though, and is also the recommended packaging method, which is why I switched for all projects. But there's no reason why you couldn't have a setup.py alongside a pyproject.toml. setup.py would need to updated for the new plugin structure though.