hostcheck: fix sizing and height calculation for status label

[Heckie75]

Fix hostcheck@schorschii desklet sizing by removing incorrect global.ui_scale scaling from label dimension calculations, using the label’s preferred rendered height, and making the canvas height match the actual label height; also add box-sizing: border-box to the status box stylesheet so the layout behaves consistently.

[rcalixte]

cc @schorschii

[schorschii]

I am not convinced by the change. The desklet now has a too big padding at the bottom (not equal with top padding):

What exactly are you trying to fix?

[Heckie75]

@schorschii Actually the change fixes the broken design in case that scaling is configured. In my case I have a 4K screen and set the scaling to 125%. Without this fix it looks like this:

The red/green panel is too big. Also the font is far to big.