The following is implemented.
1. Configuring area as NSSA.
2. Generating Type 7 LSA.
3. Conversion of Type 7 to Type 5 ( Default Behavior).
4. NSSA ABR selection.
Reviewed-by: Rafael Zalamena <rzalamena@opensourcerouting.org>
Co-authored-by: Kaushik <kaushiknath.null@gmail.com>
Co-authored-by: Soman K.S <somanks@gmail.com>
Signed-off-by: Kaushik <kaushiknath.null@gmail.com>
