Aspect Ratio

#### Predefined Aspect Ratio
Define some popular aspect ratios, so that the user may be able to easily choose from them. These predefined aspect ratios can also be filtered on the basis of the aspect ratios used on various social media platform.

#### Set the height and Width
An option to manually set the height and width of the image in pixels. The height/width of the image should change when the user changes the value of height/width and presses enter.

#### Set the Aspect Ratio manually
An option to manually set the aspect ratio (height vs width). The aspect ratio of the image should change when the user changes the value of aspect ratio and presses enter.

No files, tests, or entry points are named in the issue. Start by locating the image-editing UI and its existing size controls, then identify where changes are applied and how the interface is tested; done means predefined, pixel, and manual aspect-ratio controls all update the image after Enter.

Written by the indexing model from the issue text.