Junit5: Review experimental APIs and decide which to promote in 5.7

[marcphilipp]

We should promote widely adopted APIs such as parameterized tests for 5.7.

See https://junit.org/junit5/docs/current/user-guide/#api-evolution-experimental-apis.

[marcphilipp]

Team decision: Promote

• [x] org.junit.jupiter.params to STABLE
• [x] @TestMethodOrder and its dependencies to STABLE
• [x] @DisplayNameGeneration and its dependencies to STABLE
• [x] Extension functions in Assertions.kt that were introduced in 5.1 to STABLE
• [x] @Timeout to STABLE
• [x] TestInstanceFactory and its dependencies to STABLE
• [x] TestInstancePreDestroyCallback to STABLE
• [x] TestInstances to STABLE
• [x] TestWatcher to STABLE
• [x] org.junit.jupiter.migrationsupport to STABLE
• [x] LauncherConstants and LauncherConfig to STABLE
• [x] LegacyXmlReportGeneratingListener to STABLE
• [x] org.junit.platform.testkit.engine to MAINTAINED

[marcphilipp]

_in progress_

[marcphilipp]

Done in d6907b1360822a5802c55c1046095b7bd4d9a20d...58bb81bfee73c5154b0a223ba68f7677bb98376d.