[AMORO-4203][format-iceberg] Migrate tests from JUnit 4 to JUnit 5

[lintingbin]

What is this PR for?

Closes part of #4203 (Step 3 — amoro-format-iceberg). 49 test files migrated to JUnit Jupiter, including 15 @RunWith(Parameterized.class) classes rewritten as @ParameterizedTest @MethodSource per @czy006's preference expressed on #4004.

Dual-mode test bases (the central design decision)

CatalogTestBase, TableTestBase, and TableDataTestBase are still extended by ~19 JUnit 4 @RunWith(Parameterized.class) subclasses in amoro-format-mixed-hive and amoro-ams that Steps 4 and 8 of #4203 will migrate later. Migrating them now would either force a 200+ file mega-PR or drop into the same trap as #4004. Instead, this PR keeps the JUnit 4 surface intact and adds a parallel JUnit 5 surface:

• The original (CatalogTestHelper, TableTestHelper) constructor and @Before setupCatalog() / @Before setupTable() are preserved — JUnit 4 Parameterized callers continue to work unchanged.
• A no-arg constructor is added.
• New protected void setupCatalog(CatalogTestHelper) / protected void setupTable(CatalogTestHelper, TableTestHelper) entry points let JUnit 5 callers initialise the catalog/table state explicitly from their @ParameterizedTest method body.
• @ClassRule TestAms and @Rule TemporaryFolder are kept for the JUnit 4 path. For the JUnit 5 path we add @BeforeAll startTestAms() / @AfterAll stopTestAms() calling the public before() / after() of TestAms directly, and the TemporaryFolder is initialised manually inside setupCatalog(helper) because JUnit 4 @Rule does not fire under the JUnit Platform engine.

Cross-module compile is verified: mvn -pl amoro-format-mixed-hive,amoro-ams -am test-compile builds cleanly. All this dual plumbing is removed in the closing PR of #4203.

Files intentionally kept on JUnit 4 in this PR

• TestMixedCatalog, TestTaskReader, TestTaskWriter, TestTableTrashManagers — same dual-mode reasoning, they are subclassed by TestMixedHiveCatalog/TestHiveTaskReader/TestHiveTaskWriter/TestHiveTableTrashManagers in mixed-hive.
• TestIcebergAmoroCatalog, TestMixedIcebergFormatCatalog — extend TestAmoroCatalogBase in amoro-common, which the umbrella plan keeps on JUnit 4 until the closing PR.

Parameterized rewrite template

public class TestX extends TableTestBase {
  public static Stream<Arguments> parameters() {
    return Stream.of(Arguments.of(c1, t1), Arguments.of(c2, t2), ...);
  }

  @ParameterizedTest(name = "{0}, {1}")
  @MethodSource("parameters")
  public void testFoo(CatalogTestHelper c, TableTestHelper t) throws Exception {
    setupTable(c, t);
    // existing body
  }
}

TestIcebergFindFiles is a small exception: its parent org.apache.iceberg.TestBase (Iceberg 1.7.2) is already JUnit 5 native, so it migrates to @TestTemplate + ParameterizedTestExtension to match upstream's pattern.

Other mechanical changes

• org.junit.* → org.junit.jupiter.api.*
• @Before / @After → @BeforeEach / @AfterEach
• Assert.assertX(...) → Assertions.assertX(...) with corrected message-arg order (JUnit 4's leading-message position flips to trailing in JUnit 5)
• @Rule TemporaryFolder → @TempDir Path in non-dual-mode files; temp.newFolder() → Files.createTempDirectory(temp, "...").toFile()
• @Test(expected = X.class) → Assertions.assertThrows(X.class, () -> ...)
• @Ignore → @Disabled
• org.junit.Assume → Assumptions

Type of change

• Improvement (test infrastructure)

How was this patch tested?

• mvn -pl amoro-format-iceberg -am test → 501 run, 0 failures, 0 errors, 5 skipped (skipped via JUnit 5 Assumptions.assumeTrue/False, not failures). Both Vintage and Jupiter engines run.
• mvn -pl amoro-format-mixed-hive,amoro-ams -am test-compile → BUILD SUCCESS (dual-mode contract preserved for downstream Steps 4 / 8).
• mvn -pl amoro-format-iceberg spotless:check clean.

[lintingbin]

@czy006 @xxubai CI is green. This is the iceberg piece of #4203 — 49 files, 15 @RunWith(Parameterized.class) classes rewritten as @ParameterizedTest @MethodSource per your guidance on #4004. The dual-mode design on CatalogTestBase/TableTestBase/TableDataTestBase is the central design decision and is flagged in the PR body; cross-module test-compile of amoro-format-mixed-hive and amoro-ams is verified so Steps 4 and 8 stay unblocked. Review appreciated.