Backend Maven GAV support

{
   "name":"aaaa",
   "tags":[
      "kafka"
   ],
   "flows":[
      {
         "id":"-M3GWPcx-rxLiuukCqSj",
         "dependencies":[
            {
               "type":"EXTENSION_TAG",
               "id":"io.syndesis.extensions:syndesis-library-test-driver"
            },
            {
               "type":"MAVEN",
               "id":"org.mongodb:mongo-java-driver:3.12.2"
            }
...