pathd. TED support . Validation of candidate path - [part 2/4]

pathd. TED support . Validation of candidate path - [part 2/4]

    - Explicit segment list nai will be resolved to corresponded sid.
    - Dynamic segment list (from pce) will be validated.
    - If segment list could not be resolved or validated won't be used.
    - Now this new config is supported

segment-list sl-1
 index 10  nai prefix 10.1.2.1/32 iface 1
 index 30  nai adjacency 10.2.5.2 10.2.5.5
 index 40  nai prefix 10.10.10.5/32 algorithm 0

Signed-off-by: Javier Garcia <javier.garcia@voltanet.io>