cFE cmd/tlm packet clean up

[dmknutsen]

Is your feature request related to a problem? Please describe.
cFE telemetry/command packets could be organized such that variables are ordered in descending size to reduce overall length. This would make them easier to maintain and remove some of the alignment issues/reduce required padding.

There's also configurable length elements before spares, which doesn't make sense if the configuration changes.

Also should standardize spare/alignment names, many no longer make sense (why "4" in example):

cFE/modules/tbl/fsw/inc/cfe_tbl_msg.h

Lines 829 to 830 in 82c1bd4

	uint8 ByteAlign4; /**< \cfetlmmnemonic \TBL_SPARE4
	\brief Spare byte to maintain byte alignment */

Requester Info
Dan Knutsen
NASA/Goddard

[skliper]

Note cmd/tlm structure updates are currently deferred to delivery from data center and definition of generic data descriptions.