feat: image support (#4011)

Co-authored-by: Emil Atanasov <heitara@gmail.com>
Co-authored-by: Aakansha Doshi <aakansha1216@gmail.com>

src/element/typeChecks.ts

@@ -5,6 +5,8 @@ import {
   ExcalidrawBindableElement,
   ExcalidrawGenericElement,
   ExcalidrawFreeDrawElement,
+  InitializedExcalidrawImageElement,
+  ExcalidrawImageElement,
 } from "./types";
 
 export const isGenericElement = (
@@ -19,6 +21,18 @@ export const isGenericElement = (
   );
 };
 
+export const isInitializedImageElement = (
+  element: ExcalidrawElement | null,
+): element is InitializedExcalidrawImageElement => {
+  return !!element && element.type === "image" && !!element.fileId;
+};
+
+export const isImageElement = (
+  element: ExcalidrawElement | null,
+): element is ExcalidrawImageElement => {
+  return !!element && element.type === "image";
+};
+
 export const isTextElement = (
   element: ExcalidrawElement | null,
 ): element is ExcalidrawTextElement => {