feat: add sidebar for libraries panel (#5274)

Co-authored-by: dwelle <luzar.david@gmail.com>
Co-authored-by: Aakansha Doshi <aakansha1216@gmail.com>

src/packages/excalidraw/CHANGELOG.md

@@ -17,6 +17,8 @@ Please add the latest change on the top under the correct section.
 
 #### Features
 
+- Add `[UIOptions.dockedSidebarBreakpoint]`(https://github.com/excalidraw/excalidraw/blob/master/src/packages/excalidraw/README.md#dockedSidebarBreakpoint) to customize at which point to break from the docked sidebar [#5274](https://github.com/excalidraw/excalidraw/pull/5274).
+
 - Added support for supplying user `id` in the Collaborator object (see `collaborators` in [`updateScene()`](https://github.com/excalidraw/excalidraw/blob/master/src/packages/excalidraw/README.md#updateScene)), which will be used to deduplicate users when rendering collaborator avatar list. Cursors will still be rendered for every user. [#5309](https://github.com/excalidraw/excalidraw/pull/5309)
 
 - Export API to [set](https://github.com/excalidraw/excalidraw/blob/master/src/packages/excalidraw/README.md#setCursor) and [reset](https://github.com/excalidraw/excalidraw/blob/master/src/packages/excalidraw/README.md#resetCursor) mouse cursor on the canvas [#5215](https://github.com/excalidraw/excalidraw/pull/5215).

src/packages/excalidraw/README_NEXT.md

@@ -639,7 +639,7 @@ This prop sets the name of the drawing which will be used when exporting the dra
 
 #### `UIOptions`
 
-This prop can be used to customise UI of Excalidraw. Currently we support customising only [`canvasActions`](#canvasActions). It accepts the below parameters
+This prop can be used to customise UI of Excalidraw. Currently we support customising [`canvasActions`](#canvasActions) and [`dockedSidebarBreakpoint`](dockedSidebarBreakpoint). It accepts the below parameters
 
 <pre>
 { canvasActions: <a href="https://github.com/excalidraw/excalidraw/blob/master/src/types.ts#L208"> CanvasActions<a/> }
@@ -657,6 +657,12 @@ This prop can be used to customise UI of Excalidraw. Currently we support custom
 | `theme` | boolean | true | Implies whether to show `Theme toggle` |
 | `saveAsImage` | boolean | true | Implies whether to show `Save as image button` |
 
+##### `dockedSidebarBreakpoint`
+
+This prop indicates at what point should we break to a docked, permanent sidebar. If not passed it defaults to [`MQ_RIGHT_SIDEBAR_MAX_WIDTH_PORTRAIT`](https://github.com/excalidraw/excalidraw/blob/master/src/constants.ts#L167). If the `width` of the `excalidraw` container exceeds `dockedSidebarBreakpoint`, the sidebar will be dockable. If user choses to dock the sidebar, it will push the right part of the UI towards the left, making space for the sidebar as shown below.
+
+![image](https://user-images.githubusercontent.com/11256141/174664866-c698c3fa-197b-43ff-956c-d79852c7b326.png)
+
 #### `exportOpts`
 
 The below attributes can be set in `UIOptions.canvasActions.export` to customize the export dialog. If `UIOptions.canvasActions.export` is `false` the export button will not be rendered.

src/packages/excalidraw/index.tsx

@@ -44,6 +44,7 @@ const ExcalidrawBase = (props: ExcalidrawProps) => {
   const canvasActions = props.UIOptions?.canvasActions;
 
   const UIOptions: AppProps["UIOptions"] = {
+    ...props.UIOptions,
     canvasActions: {
       ...DEFAULT_UI_OPTIONS.canvasActions,
       ...canvasActions,