Eclipse Californium (Cf) CoAP Framework 3.4.0

Minor release. Includes block1 usage clarification and improved recent handshakes cleanup.

• 10e9220a7 2022-03-17 Improve cleanup of handshakes.
• e317d596d 2022-03-17 Apply source formatting.
• d7bddf245 2022-03-20 Use ReadWriteLock instead of synchronization for PSK store.
• 67ad63616 2022-03-15 Cleanup scandium unit tests.
• c46c2f8e7 2022-03-14 Introduce marker for internal created response.
• 469e35994 2022-03-15 Use more descriptive exception on intrinsic signature algorithm error.
• 99f6e4048 2022-03-15 Don't log stacktrace, if jul-logging bridge is not available.
• e240bb57f 2022-03-15 Fix deprecate EC by using JceNames.EC.
• c1accc92f 2022-03-14 Add persistent component.
• df18c8d61 2022-03-11 Add support for critical custom options.
• 04484c215 2022-03-11 Remove block1 in error response.
• 642d22409 2022-03-11 Demonstrate to load a pem file for client credentials.
• 6e301335a 2022-03-10 Do not log a warning message using ZGC, when memory usage reaches 80%.
• e6a2b9971 2022-03-01 Support dtls graceful restart also for single server.
• db1f8ee86 2022-03-01 Enable DtlsRole.BOTH for cluster management.
• a8193a812 2022-02-22 Add build version to plugtest servers.
• 1f0a6b6a6 2022-02-26 Fix broken encryption on dtls graceful restart.