Merge remote-tracking branch 'restricted/iotssl-1398_backport-1.3' into mbedtls-1.3-restricted

* restricted/iotssl-1398_backport-1.3:
  Add ChangeLog entry
  Ensure application data records are not kept when fully processed
  Add hard assertion to ssl_read_record
  Fix mbedtls_ssl_read
  Simplify retaining of messages for future processing