taglist: Register tags for multiple info
taglist: Register tags for multiple info

:Release Notes:
 Add the string merge function to add multiple info

:Detailed Notes:
 Add the string merge function to add multiple info
 multiple info are added as string sperated by comma

Change-Id: Ic2fbe74e41b304b567b4df64b0688d54adcadaf9
Reviewed-on: https://gpro.lgsvl.com/50709
Reviewed-by: Dongil Park <c2ea9f0f1daafef0298afe5eb0544e377be997ff@lge.com>
Tested-by: Dongil Park <c2ea9f0f1daafef0298afe5eb0544e377be997ff@lge.com>

justinjoy/gstreamer,justinjoy/gstreamer,justinjoy/gstreamer,justinjoy/gstreamer,justinjoy/gstreamer