Add setWidthFromRatio and setHeightFromRatio to Settings

Example usage: (when width or height is known and the other aspect needs to be set using a specific ratio)

settings.setWidth(800);
settings.setHeightFromRatio(16 / 9);

[shubhankarb180]

@nandhae You can work too. I was not able to add as I don’t know much kotlin.

[nandhae]

@AlmasB Raised a PR #675 with two simple functions which takes ratio as a fraction. The clarifications i would be needing are,

1. Assumed that ratio would be fraction and did not try to read as string. Eg: “16:9”. Please verify if this is okay.
2. Rounded result height and width to int. Worried if it will have precision errors.
3. Could not add unit tests, since I could not access these methods in “GameSettingsTest”

Any suggestions or directions on these points would help. Would be happy to refactor and enhance.