HVR allow timestamp format for {hvr_cap_tstamp}, but not for {hvr_cap_entry_timestamp}.

Details of this request can be reviewed via RD-1281046.

{hvr_cap_entry_timestamp} is stored as a string in HVR. Therefore, it is not possible to specify a timestamp format similar to {hvr_cap_tstamp %[utc]%Y%m%d%H%M%S}.