Enable export and import of SDN configuration

resolves #269 (closed)

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

dev_env_data/clab/basic_setup.yaml

+name: gosdn_csbi_arista_base
+
+mgmt:
+  network: gosdn-csbi-arista-base-net
+  ipv4_subnet: 172.100.0.0/16
+  ipv6_subnet: 2001:db8::/64
+
+topology:
+  kinds:
+    ceos:
+      image: registry.code.fbi.h-da.de/danet/containers/ceos:4.28.2F
+  nodes:
+    ceos0:
+      kind: ceos
+      mgmt_ipv4: 172.100.0.11
+
+    ceos1:
+      kind: ceos
+      mgmt_ipv4: 172.100.0.12
+
+  links:
+    - endpoints: ["ceos0:eth1","ceos1:eth1"]