Dropdown Component - Keyboard Navigation and accessibility

• I have searched the issues of this repository and believe that this is not a duplicate.

What problem does this feature solve?

The current implementation of Dropdown is not accessible for keyboard users.

Features that would improve keyboard navigation: escape key to close - when the menu is open pressing ESC to close the current dropdown arrow key nav - use up/down arrow keys to traverse options in the dropdown

What does the proposed API look like?

Adding a keydown handler to Dropdown similar to Cascader or Select:

  handleKeyDown = (e: React.KeyboardEvent<HTMLInputElement>) => {
    // SPACE => https://github.com/ant-design/ant-design/issues/16871
    if (e.keyCode === KeyCode.BACKSPACE || e.keyCode === KeyCode.SPACE) {
      e.stopPropagation();
    }
  };

[codewitch]

this isnt actually fixed by that PR. keyboard navigation works for regular menus but not for dropdowns

[afc163]

Fixed in https://github.com/ant-design/ant-design/pull/30382