Make left panel height flexible to avoid overflow (#1169)

* Make overall left menu scrollable

* Make only mid-left panel scrollable

* Update src/styles.scss

* Update src/styles.scss

* Update src/components/LayerUI.tsx

* Remove unused class

* Move the scrolling role to Island

Co-authored-by: Lipis <lipiridis@gmail.com>

src/components/Island.tsx

@@ -2,12 +2,16 @@ import "./Island.css";
 
 import React from "react";
 
-type IslandProps = { children: React.ReactNode; padding?: number };
+type IslandProps = {
+  children: React.ReactNode;
+  padding?: number;
+  className?: string;
+};
 
 export const Island = React.forwardRef<HTMLDivElement, IslandProps>(
-  ({ children, padding }, ref) => (
+  ({ children, padding, className }, ref) => (
     <div
-      className="Island"
+      className={`${className ?? ""} Island`}
       style={{ "--padding": padding } as React.CSSProperties}
       ref={ref}
     >