RFR: 7903752: Include duration information in JUnit-based tests

[Christian Stein]

Please review this change to include duration information in JUnit-based tests.

For example, see this excerpt from a `.jtr` file generated for the `JupiterTests` self-test.

Before:

#section:junit
...
----------System.err:(21/1306)----------
STARTED    JupiterTests::nullEmptyAndBlankStrings '[1] test('null')'
SUCCESSFUL JupiterTests::nullEmptyAndBlankStrings '[1] test('null')'
STARTED    JupiterTests::nullEmptyAndBlankStrings '[2] test('')'
SUCCESSFUL JupiterTests::nullEmptyAndBlankStrings '[2] test('')'
...

After:

#section:junit
...
----------System.err:(21/1306)----------
STARTED    JupiterTests::nullEmptyAndBlankStrings '[1] test('null')'
SUCCESSFUL JupiterTests::nullEmptyAndBlankStrings '[1] test('null')' [24ms]
STARTED    JupiterTests::nullEmptyAndBlankStrings '[2] test('')'
SUCCESSFUL JupiterTests::nullEmptyAndBlankStrings '[2] test('')' [1ms]
...

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

Commit messages:
 - 7903752: Include duration information in JUnit-based tests

Changes: https://git.openjdk.org/jtreg/pull/206/files
  Webrev: https://webrevs.openjdk.org/?repo=jtreg&pr=206&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903752
  Stats: 12 lines in 1 file changed: 11 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jtreg/pull/206.diff
  Fetch: git fetch https://git.openjdk.org/jtreg.git pull/206/head:pull/206

PR: https://git.openjdk.org/jtreg/pull/206