Fix: Use the desktop scale in plugin window

[pawel-ulita]

This makes sure that the plugin window itself follows the desktop scale set in the settings. This affects the size of the buttons at the top, and also the size of the contents of the built-in plugins.

Before vs after

Before

After

I have only tested in on Linux, so I'm not sure about the consequences on other operating systems.

[CLAassistant]

All committers have signed the CLA.

[pawel-ulita]

I see this may conflict with: #478 At the same time, maybe this is not a problem any more? I don't experience anything like what the issue describes with the native and 3rd party plugins.

[mfisher31]

Hey thanks for this @pawel-ulita.

[mfisher31]

I see this may conflict with: #478 At the same time, maybe this is not a problem any more? I don't experience anything like what the issue describes with the native and 3rd party plugins.

Ahh yeah, forgot about that one. Will need to test this on other OS and high res monitors too. #478 effectively bypasses the scale factor as configured in Element Preferences on plugin windows. We may want a manual scale factor setting just for the plugin window on a per-node basis. It's impossible to predict how all 3rd party plugins will handle scale. Kind of like a manual override. IDK.