Preserve TestSetup suite fixtures as static Jupiter lifecycle methods.

[motlin]

What's changed?

MigrateJUnitTestCase preserves one-time fixtures from a suite() method returning an anonymous TestSetup around new TestSuite(CurrentTest.class). The decorator's setUp() and tearDown() bodies become static @BeforeAll and @AfterAll methods on the test class.

What's your motivation?

• Fixes JUnit 4 to 5 migration discards the one-time setup a TestSetup decorator performed, breaking tests at run time #1110. Removing suite() currently discards the setup and teardown performed by TestSetup, leaving tests that compile but fail at runtime because their shared resources were never initialized.