RFR: 8316025: Use testUI() method of PassFailJFrame.Builder in FileChooserSymLinkTest.java [v2]

[Alexey Ivanov]

> This update to `FileChooserSymLinkTest.java` demonstrates the usage of the `testUI` method of the `PassFailJFrame.Builder` class to streamline creating the UI for manual tests.
> 
> The [`main` method](https://github.com/aivanov-jdk/jdk/blob/cb1835527d718226f1c6fdd85ff5986703ea356f/test/jdk/javax/swing/JFileChooser/FileChooserSymLinkTest.java#L110-L118) is a simple sequence of calls:
> 
> 
>     public static void main(String[] args) throws Exception {
>         PassFailJFrame.builder()
>                       .instructions(INSTRUCTIONS)
>                       .rows(35)
>                       .columns(50)
>                       .testUI(FileChooserSymLinkTest::createTestUI)
>                       .build()
>                       .awaitAndCheck();
>     }
> 
> 
> It's the most streamlined way of creating a manual test.
> 
> This change depends on #15665 and [JDK-8294156](https://bugs.openjdk.org/browse/JDK-8294156) as well as #15661, both of which depend on #15660.

Alexey Ivanov has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - 8316025: Update the return type of createTestUI
   
   PassFailJFrame now supports creating a list of test windows
 - Merge branch '8294156-func-manual-TestUI' into 8316025-testUI-SymLinkTest
 - Use testUI() and builder pattern to create test UI

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15666/files
  - new: https://git.openjdk.org/jdk/pull/15666/files/cb183552..a813fe85

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15666&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15666&range=00-01

  Stats: 262 lines in 2 files changed: 202 ins; 18 del; 42 mod
  Patch: https://git.openjdk.org/jdk/pull/15666.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15666/head:pull/15666

PR: https://git.openjdk.org/jdk/pull/15666