[jdk25u-dev] RFR: 8365776: Convert JShell tests to use JUnit instead of TestNG

[Goetz Lindenmaier]

I backport this for parity with 25.0.3-oracle.

A hand full of trivial resolves needed:

test/langtools/jdk/jshell/ClassesTest.java
Trivial resolve because "8260555: Change the default TIMEOUT_FACTOR from 4 to 1" is not in 25.

test/langtools/jdk/jshell/CompletionSuggestionTest.java
Trivial resolve because "8260555: Change the default TIMEOUT_FACTOR from 4 to 1" is not in 25.
Omitted @Test for subtest testCustomClassPathIndexing() which is not in 25.

test/langtools/jdk/jshell/InputUITest.java
Omitted changing two subtests not in 25.

test/langtools/jdk/jshell/JdiHangingLaunchExecutionControlTest.java
test/langtools/jdk/jshell/JdiHangingListenExecutionControlTest.java
Trivial resolve.

test/langtools/jdk/jshell/SnippetHighlightTest.java
Omitted subtest not in 25

test/langtools/jdk/jshell/ToolCommandOptionTest.java
Omitted. Test class not in 25

test/langtools/jdk/jshell/ToolLocalSimpleTest.java
test/langtools/jdk/jshell/ToolSimpleTest.java
test/langtools/jdk/jshell/VariablesTest.java
Trivial resolve because "8260555: Change the default TIMEOUT_FACTOR from 4 to 1" is not in 25.

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Commit messages:
 - resolves
 - backport b0ca9bf61e0390a3b022a0915eacabb0cfd92e93

Changes: https://git.openjdk.org/jdk25u-dev/pull/325/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u-dev&pr=325&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8365776
  Stats: 1765 lines in 122 files changed: 736 ins; 215 del; 814 mod
  Patch: https://git.openjdk.org/jdk25u-dev/pull/325.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u-dev.git pull/325/head:pull/325

PR: https://git.openjdk.org/jdk25u-dev/pull/325