Updating Graph Output for arcade-visualization - #193

Updated PatchOutputSerializer to output SITES.GRAPH.json files in this format:

{
"from": {
"x": 10,
"y": 30,
"z": 0,
"pressure": 56.99829015221532,
"oxygen": 79.47211936116219
},
"to": {
"x": 12,
"y": 28,
"z": 0,
"pressure": 56.93131181220028,
"oxygen": 79.47211638092995
},
"type": "ARTERY",
"sign": -1,
"radius": 24.412305860254712,
"length": 34.64101615137755,
"wall": 6.110612101951247,
"shear": 0.02360057388781724,
"stress": 227.5782068382533,
"flow": 7.882493452400926E8,
"fraction": "GLUCOSE:0.9999999877956426,",
"transport": "OXYGEN:-1.446155143779032,GLUCOSE:0.0,"
}

Size: xsmall

Summary:
Added sign, fraction, and transport fields to the SiteEdge serializer
Added the SiteEdge getFraction() and getTransport() functions from angiogenesis branch