PDI-10942 - Job get emails JobEntry does not mark emails as 'read' when load emails content.

Added fix. Remote email folder is always attempt to open in RW mode if
protocol is not POP3, attempt to read email content marks email as read.
Junit tests added.
Merge pull request #215 from prakapenka/PDI-10942

PDI-10942 - Job get emails JobEntry does not mark emails as 'read' when load emails content