RFR: 8339728 : [Accessibility,Windows,JAWS] Bug in the getKeyChar method of the AccessBridge class

[Abhishek Kumar]

For a JMenuItem with a shortcut like _Ctrl + Comma_, the `getKeyChar` method of the `AccessBridge` class cuts the _Comma_ text to the first character and hence transfers `C (instead of Comma)` via the `AccessBridge` API. For a shortcut _Ctrl + Comma_ in a menu item, screen readers announce _Ctrl + C_ instead of _Ctrl + Comma_ as shortcut. Same issue exists for **Enter, Period and other keys** as well where only the first character is returned from the getKeyChar method. 

Proposed fix is to ensure that the _char representation of the shortcuts_ is returned by the `getKeyChar` method and it worked fine except for **"Enter"** key. It is unclear to me why it has not announced by AT (JAWS) but I think that may be due to the char representation of the Enter key which is a Line Feed.

AT was also not able to announce the _Tab and Space_ key as a shortcut. Adding these keys in the control key list in _AccessBridge_ and in supported control code list in _AccessBridgePackages_ files enabled them to be announced by AT.

Manual test case is added to verify the shortcut for JMenuItems.

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Commit messages:
 - MenuItem shortcut accessibility fix

Changes: https://git.openjdk.org/jdk/pull/22822/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22822&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8339728
  Stats: 124 lines in 3 files changed: 117 ins; 2 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/22822.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22822/head:pull/22822

PR: https://git.openjdk.org/jdk/pull/22822