feat: allow host to pass color for collaborators (#2943)

* feat: allow host to pass color for collaborators

* remove user prop as its not used anywhere

* update changelog and readme

* add pr link

src/excalidraw-app/index.tsx

@@ -281,7 +281,6 @@ function ExcalidrawWrapper() {
         width={dimensions.width}
         height={dimensions.height}
         initialData={initialStatePromiseRef.current.promise}
-        user={{ name: collabAPI?.username }}
         onCollabButtonClick={collabAPI?.onCollabButtonClick}
         isCollaborating={collabAPI?.isCollaborating()}
         onPointerUpdate={collabAPI?.onPointerUpdate}