Command DISPLAY PROFILE, enhance msg DSNT753I with another timestamp

Summary:
Add the timestamp of when the START PROFILE command started to message DSNT753I.

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Currently, the output of a DISPLAY PROFILE command, when the profile STATUS is ON, shows a message DSNT753I similar to the following:

DSNT753I +DB2P DSNT1DSP DISPLAY PROFILE REPORT FOLLOWS:
STATUS = ON
TIMESTAMP = 2018-09-14-12.34.56.123456
PUSHOUTS = 0 OUT OF 10000
DISPLAY PROFILE REPORT COMPLETE.

According to feedback received: "[...] the timestamp value from DISPLAY PROFILE is the time START PROFILE command completed successfully."

The timestamp of when the START PROFILE command *started* is not shown, however, between the start and end time of the command, profiles are activated and registered in SYSIBM.DSN_PROFILE_HISTORY and SYSIBM.DSN_ATTIBUTE_HISTORY tables with their own 'activation' timestamps. The latter timestamps are always smaller as the TIMESTAMP shown in message DSNT753I.

So, as it is unknown how long the execution time of the START PROFILE command was, to query the history tables for active profiles one has to extract the TIMESTAMP displayed in message DSNT753I and use it in a query similar to:

SELECT * FROM SYSIBM.DSN_PROFILE_HISTORY
WHERE PROFILE_TIMESTAMP <= 'timestamp'
AND PROFILE_TIMESTAMP >= 'timestamp' - 2 MINUTES

But also here, it's not sure whether the resulting rows match the active profiles (as more than one START PROFILE commands may have been executed within these (e.g.) 2 minutes, each command with, for a specific PROFILEID, different Y/N values in the PROFILE_ENABLED column).

If message DSNT753I would also show the *start time* of when the START PROFILE command *started* with the activation of all ENABLED=Y profiles, the problem would disappear - similar to:

DSNT753I +DB2P DSNT1DSP DISPLAY PROFILE REPORT FOLLOWS:
STATUS = ON
TIMESTAMP = 2018-09-14-12.34.56.123456
STARTED = 2018-09-14-12.34.22.123456
PUSHOUTS = 0 OUT OF 10000
DISPLAY PROFILE REPORT COMPLETE.