Node Definition: Move Certificate SAN under Certificate stanza

[steiler]

Implement #1815

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (be855fa) 51.27% compared to head (452cc58) 51.23%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1821      +/-   ##
==========================================
- Coverage   51.27%   51.23%   -0.05%     
==========================================
  Files         147      147              
  Lines       14273    14266       -7     
==========================================
- Hits         7319     7309      -10     
- Misses       6134     6137       +3     
  Partials      820      820              

Files	Coverage Δ
clab/config.go	66.58% <ø> (-0.09%)	⬇️
nodes/default_node.go	57.87% <100.00%> (+0.78%)	⬆️
nodes/srl/srl.go	58.26% <100.00%> (-0.32%)	⬇️
types/node_definition.go	94.89% <ø> (-0.11%)	⬇️
types/topology.go	68.23% <ø> (+0.26%)	⬆️
types/types.go	63.15% <100.00%> (+0.99%)	⬆️

... and 1 file with indirect coverage changes