Fix double scrollbars on collapsible document page

NXP-27652 introduced double vertical scrollbars on collapsible page. This is happens because we introduced css variables for both min-height and height on nuxeo-results, meaning that the min-height is overruled in some cases. This can be fixed by defining both css variables on nuxeo-document-content (and nuxeo-document-trash-content). But because this is reductant, we should refactor these variables. We can keep --nuxeo-results-view-height and remove --nuxeo-results-view-min-height. However, we do have other variables that used to rely on the deprecated variable but will now rely on the new variable, namely --nuxeo-document-content-min-height. Because the name is inconsistent, we should deprecate --nuxeo-document-content-min-height and instead name it --nuxeo-document-content-height, while still keeping the first as fallback, to keep compatibility. We should do the name for --nuxeo-document-trash-content-min-height.