feat: Calculate width/height of canvas based on container dimensions (".excalidraw" selector) & remove props width & height (#3379)

* Remove width/height from the ".excalidraw" container so it will sized automatically.
* updated all ref calculation to ".excalidraw" instead of parent since now ".excalidraw" will get resized
* Remove props width/height as its not needed anymore.
* Resize handler is also not needed anymore.
* Position absolute canvas due to #3379 (comment)

* move css to style and remove one extra rerendering

* factor out mock logic for test

* set height, width so as to avoid unnecessary updates of regression snap

* better mock

* better type checking and omit width,height from getDefaultAppState and also restore

* revert

* default to window dimensions in constructor

* update docs

* update

* update

* tweaks

src/packages/utils.ts

@@ -33,7 +33,7 @@ export const exportToCanvas = ({
   } = restoredAppState;
   return _exportToCanvas(
     getNonDeletedElements(restoredElements),
-    { ...restoredAppState, offsetTop: 0, offsetLeft: 0 },
+    { ...restoredAppState, offsetTop: 0, offsetLeft: 0, width: 0, height: 0 },
     { exportBackground, viewBackgroundColor, shouldAddWatermark },
     (width: number, height: number) => {
       const canvas = document.createElement("canvas");