[Improvement] Make menus scrollable if they overflow off-screen #390
Description
Take this code
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<link rel="stylesheet" href="https://unpkg.com/mdui@2/mdui.css">
<script src="https://unpkg.com/mdui@2/mdui.global.js"></script>
</head>
<body>
<mdui-select value="item-1">
<mdui-menu-item value="item-1">Item 1</mdui-menu-item>
<mdui-menu-item value="item-2">Item 2</mdui-menu-item>
<mdui-menu-item value="item-1">Item 1</mdui-menu-item>
<mdui-menu-item value="item-2">Item 2</mdui-menu-item>
<mdui-menu-item value="item-1">Item 1</mdui-menu-item>
<mdui-menu-item value="item-2">Item 2</mdui-menu-item>
<mdui-menu-item value="item-1">Item 1</mdui-menu-item>
<mdui-menu-item value="item-2">Item 2</mdui-menu-item>
<mdui-menu-item value="item-1">Item 1</mdui-menu-item>
<mdui-menu-item value="item-2">Item 2</mdui-menu-item>
<mdui-menu-item value="item-1">Item 1</mdui-menu-item>
<mdui-menu-item value="item-2">Item 2</mdui-menu-item>
<mdui-menu-item value="item-1">Item 1</mdui-menu-item>
<mdui-menu-item value="item-2">Item 2</mdui-menu-item>
<mdui-menu-item value="item-1">Item 1</mdui-menu-item>
<mdui-menu-item value="item-2">Item 2</mdui-menu-item>
<!--...-->
</mdui-select>
</body>
</html>On small windows or when the menu is not placed at the top of the screen, the options overflow off-screen like this
What should happen is the options become scrollable, like this (MUI's select given as an example)
