Review of `ol/style/Image` and subclass options

Following on from https://github.com/openlayers/openlayers/pull/13975#issuecomment-1216276968 here are the options supported by the Mapbox specification https://docs.mapbox.com/mapbox-gl-js/style-spec/layers/#symbol and their equivalents in OpenLayers.

icon-allow-overlap declutterMode

icon-anchor Similar to anchorOrigin but has more options so ol-mapbox-style sets an appropriate fractional anchor.

icon-color color

icon-halo-blur n/a

icon-halo-color n/a

icon-halo-width n/a

icon-ignore-placement declutterMode

icon-image Derived from sprite related options img, imgSize, offset, offsetOrigin, size, src.

icon-keep-upright n/a Relates to line placement icons, similar to keeping line placement text upright - Mapbox has a similar text-keep-upright option but OpenLayers does this unconditionally

icon-offset Corresponds to the current meaning of displacement "Each component is multiplied by the value of icon-size to obtain the final offset in pixels" (except OpenLayer is positive y up, Mapbox positive y down). Similarly ol-mapbox-style multiplies text-offset by text-size when setting offsetX and offsetY

icon-opacity opacity

icon-optional n/a

icon-padding n/a

icon-pitch-alignment n/a

icon-rotate rotation (OpenLayers uses radians, Mapbox degrees)

icon-rotation-alignment rotateWithView

icon-size scale

icon-text-fit n/a

icon-text-fit-padding n/a

icon-translate This could be achieved using anchor or displacement but unlike icon-offset the behavior is affected by icon-translate-anchor

icon-translate-anchor n/a How icon-translate relates to rotation - there is a similar text-translate-anchor option, which possibly corresponds to the differences seen in #13981 except that is text-offset not text-translate so it should not happen

Start with the Mapbox symbol-layer specification and the discussion in pull request #13975, then compare the listed options with ol/style/Image and its subclasses. A complete result would establish which options and equivalents should be supported or documented, including the unresolved points referenced in #13981.