datatype: add/move size and byte order information into data types

datatype: add/move size and byte order information into data types

Add size and type information to non-basetype types and remove the now
redundant information from the symbol tables.

This will be used to determine size and byteorder of set members without
analyzing the ruleset for incremental update operations.

Signed-off-by: Patrick McHardy <kaber@trash.net>