Quagga: AFI/SAFI mappings IANA to/from internal values

Quagga: AFI/SAFI mappings IANA to/from internal values

Introduce internal and IANA defintions for AFI/SAFI and mapping
functions and modify code to use these. This refactoring will
facilitate adding support for other AFI/SAFI whose IANA values
won't be suitable for internal data structure definitions (e.g.,
they are not contiguous).
The commit adds some fixes related to afi/safi testing with 'make check
' command.

Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by:   Donald Sharp <sharpd@cumulusnetworks.com>
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
Ticket: CM-11416
Reviewed By: CCR-3594 (mpls branch)
Testing Done: Not tested now, tested earlier on mpls branch