Use CFE_TIME_SysTime_t instead of individual Seconds/subseconds

[skliper]

Is your feature request related to a problem? Please describe.
Inconsistent use/definition of time structure vs individual sec/subsecs, benefits from common structure:

cFE/modules/core_api/fsw/inc/cfe_tbl_api_typedefs.h

Lines 114 to 117 in 82c1bd4

	uint32 FileCreateTimeSecs; /**< \brief File creation time from last file loaded into table */
	uint32 FileCreateTimeSubSecs; /**< \brief File creation time from last file loaded into table */
	uint32 Crc; /**< \brief Most recently calculated CRC by TBL services on table contents */
	CFE_TIME_SysTime_t TimeOfLastUpdate; /**< \brief Time when Table was last updated */

Describe the solution you'd like
Use CFE_TIME_SysTime_t

Describe alternatives you've considered
None

Additional context
Code review

Requester Info
Jacob Hageman - NASA/GSFC