Save selected preview resolution

Summary Save the state of the preview resolution similarly to how the width of the preview iframe is saved. Basic Example _No response_ Motivation When editing an item of a collection that is mostly/only displayed on wider resolutions (i.e. some teasers) the default preview is often too small: Since it only uses at most half the screen, on older non-4k-displays the default resolution is closer to a mobile/tablet resolution. If the collection is not displayed at those resolutions, the preview has to be resized every time. Detailed Design The width of the preview iframe is already kept between session. This should be extended to also keep the state of the dimensions (scaling, width, height, toggle for setting these). Additionally it would be useful to give users the option to save some defaults for dimensions/scaling, so that it is easier to switch between relevant sizes for the application. Similarly to how the Devtools of the browser offers the option to set the display size…