PNG too low resolution to use in Google slides

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Is this a BUG REPORT or FEATURE REQUEST?:
type: feature

What happened:
Default png output looks fuzzy when copied to a Google slide and scaled up.

What you wish to happen:
Possibility to export a higher resolution picture with the same proportions (i.e. not having to manually scale up plot size, figure size and font size

How to reproduce it (as minimally and precisely as possible):
Create a chart and save as png

Anything else we need to know?:
Possibly duplicate of #37