Fix wrong SR-NAI type for Path Computation

Fix wrong SR-NAI type for Path Computation

When computing a segment path for PcInitiate message, the Path Computation
Algorithms produce an SR-ERO composed by Node-SIDs (NAI Type = 1 or 2).
However, routers expect a SR-ERO composed by Adjacency-SIDs
(NAI Type = 3 or 4) with M-Flag set to 1. Indeed, Node SID NAI is only valid
for loose path while Path Computation determines strict path.

This patch set change NAI (1/2) by NAI (3/4) in the SR-ERO computed by the
Path Computation Algorithms.

JIRA: BGPCEP-913

Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>
Change-Id: Ia57b0475d764830a671f785e7444aaf37007adeb