Allow configuration of Presenter to fill the screen

[mortenbekditlevsen]

Allow configuration of Presenter to fill the screen even though the proportions of the actual screen do not align with the defaultResolution.

Currently, if you want edge-to-edge slides, you need to set the defaultResolution to something that has the same proportions as the device you are presenting from.

Maybe you don't always know these proportions, but you would still like the slides to go from edge-to-edge, so that transitions animate all the way to the edges and content takes up as much space as possible.

For an iPad presentation I set the defaultResolution to the exact dimensions of the iPad, but then the font sizes were a bit different from the 'expected' ones in the default theme. When I then started changing font sizes, I then figured that the line spacing between Words didn't match the font size.

This PR adds an option to the Presenter to do just that. This means that the defaultResolution becomes more of a guide for the size of fonts, the spacing and rest of the theme. And since the default values for defaultResolution already looks good, then there's much less customization needed by just accepting this option than trying to fiddle with the default resolution and font size.

Let me know if you agree with this - or you have other observations about the best way to produce nice, edge-to-edge slides with balanced fonts on a device you may not know beforehand. :-)