Extract Side Panel from App component (#295)

* Extract Side Panel from App component

* Refactor SidePanel component

- Remove unnecessary props (we are already passing appState as a prop)
- Remove unnecessary allback (we are already passing setState)

src/element/index.ts

@@ -10,3 +10,4 @@ export { hitTest } from "./collision";
 export { resizeTest } from "./resizeTest";
 export { isTextElement } from "./typeChecks";
 export { textWysiwyg } from "./textWysiwyg";
+export { redrawTextBoundingBox } from "./textElement";

src/element/textElement.ts

@@ -0,0 +1,9 @@
+import { measureText } from "../utils";
+import { ExcalidrawTextElement } from "./types";
+
+export const redrawTextBoundingBox = (element: ExcalidrawTextElement) => {
+  const metrics = measureText(element.text, element.font);
+  element.width = metrics.width;
+  element.height = metrics.height;
+  element.baseline = metrics.baseline;
+};