Bug fixing in topology discovery as part of CCVPN (Cross-Layer Cross-Domain VPN)...

Bug fixing in topology discovery as part of CCVPN (Cross-Layer Cross-Domain VPN) use-case.

1. Cross-layer tp-ttp relationship update.
2. Save te-link-attribute and label-restriction and relationship between them.
3. Add 3rd party controller id into network-id to make it unique for cross-domain use case.
4. Calling Base64 converter plugin to convert inter-domain-plug-id

Issue-ID: SDNC-899
Signed-off-by: Hesam Rahimi <hesam.rahimi@huawei.com>
Change-Id: I892249f8197ceb0e2d32b35a521fdbb1b833010c
(cherry picked from commit 45d198493727a8907f011a7eb49b2259037f690b [formerly a3603b522c83ffd8e8cfc0f6451697dc89a5a9a3])

Former-commit-id: 4e2740455ed0e9cdb5f21f7f3cd0bce2f60a4328