feat: add support for image sprites

BREAKING CHANGE:
IconSymbolizer.image can be a Sprite

style.ts

@@ -380,6 +380,28 @@ export interface TextSymbolizer extends BasePointSymbolizer {
   fontWeight?: Expression<'normal' | 'bold'>;
 }
 
+/**
+ * Configuration for a sprite image.
+ */
+export type Sprite = {
+  /**
+   * A path/URL to the sprite image file.
+   */
+  source: Expression<string>;
+  /**
+   * The starting position of the sprite to cut out. Origing [0, 0] is top left.
+   */
+  position: [Expression<number>, Expression<number>];
+  /**
+   * The width of the sprite.
+   */
+  width: Expression<number>;
+  /**
+   * The height of the sprite.
+   */
+  height: Expression<number>;
+};
+
 /**
  * An IconSymbolizer describes the style representation of POINT data if styled
  * with a specific icon.
@@ -423,7 +445,7 @@ export interface IconSymbolizer extends BasePointSymbolizer {
   /**
    * A path/URL to the icon image file.
    */
-  image?: Expression<string>;
+  image?: Expression<string> | Sprite;
   /**
    * An optional configuration for the image format as MIME type.
    * This might be needed if the image(path) has no filending specified. e.g. http://myserver/getImage