RFR: 8348299: Update List/ItemEventTest/ItemEventTest.java [v2]

[Alexey Ivanov]

> With this changeset, I update the `java/awt/List/ItemEventTest/ItemEventTest.java` test to improve its stability and analysis of failures of the test.
> 
> 1. Use thread-safe `StringBuffer` for `actualSelectionOrder` to track selecting/deselecting items in the list.
> 2. Enable `robot.setAutoWaitForIdle(true)` and remove `robot.waitForIdle()` from the test code.
> 3. Log `handleEvent` and `ItemListener` which helps to identify test failures.  
>     (In case of [JDK-8204221](https://bugs.openjdk.org/browse/JDK-8204221), `handleEvent` is never logged.)
> 5. Take screenshot of the list on failure;  
>     Optionally take screenshot after each mouse press+release if `-save` is passed as a parameter to the test.
> 
> The updated test passes.

Alexey Ivanov has updated the pull request incrementally with one additional commit since the last revision:

  Use setLength to reset actualSelectionOrder
  
  Co-authored-by: Aleksandr Zvegintsev <77687766+azvegint at users.noreply.github.com>

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/23238/files
  - new: https://git.openjdk.org/jdk/pull/23238/files/5a54dcff..502ab45c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23238&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23238&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 2 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/23238.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23238/head:pull/23238

PR: https://git.openjdk.org/jdk/pull/23238