[node] Add licenses list on node desc to provide a source where we can fetch licenses required for the submitter

Author: Alxiice

meshroom/core/desc/node.py

@@ -91,6 +91,9 @@ class BaseNode(object):
     documentation = ""
     category = "Other"
     plugin = None
+    # Licenses required to run the plugin
+    # Only used to select machines on the farm when the node is submitted
+    _licenses = []
 
     def __init__(self):
         super(BaseNode, self).__init__()