Add the ability to set the image size as a percentage

[kamack38]

Description

Currently, only shape size can be set by a percentage and image sizes can't.

[PaideiaDilemma]

Yup already planned :)

[kamack38]

Have you thought about allowing percentage floats? I've been playing with the new units and I found myself missing the ability to use e.g. 43.21%.

[PaideiaDilemma]

what option are you talking about?

[kamack38]

Currently, I can only set the position using integer percentages e.g. 1%, 5%, 8% and not floating point percentages e.g. 1.2% 0.3% 20.22%.

[PaideiaDilemma]

You are right. Maybe we want to change the current implementation to just take floats instead of just integers.