[IOT-1833] [IOT-1834] CTT 1.7.8.3 fixes

[IOT-1833] [IOT-1834] CTT 1.7.8.3 fixes

1. Remove bogus memset from ClearRequestContext.

2. Don't try to log already-freed block from CAAddBlockOption1.

3. Fix (read) buffer overrun due to logging non-zero-terminated
   payload as a string, from CAUpdatePayloadData

Change-Id: I0e02f7656471921098ebce1cb5e216c0934d2eb2
Signed-off-by: Dan Mihai <Daniel.Mihai@microsoft.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/17387
Reviewed-by: Nathan Heldt-Sheller <nathan.heldt-sheller@intel.com>
Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Reviewed-by: Mike Fenelon <mike.fenelon@microsoft.com>
Reviewed-by: Jaewook Jung <jw0213.jung@samsung.com>
Reviewed-by: Kevin Kane <kkane@microsoft.com>