[1110277] RHQ_EVENT table's detail field limit of 4000 character will break when a log message contains multibyte characters (UTF-8)
This is a problem in a few places, not just events.  We're not
properly protecting against the 4000 byte limit on oracle, just
the 4000 character limit declared on the varchar2 field.
- Add DatabaseType.getString() which can truncate as needed in
  a vendor-specific way.
- Use the new getString() to store safe versions of event detail,
  alert notification log message, and calltime dataset destination.