Use gene identifier as Noctua model ID

[dustine32]

As suggested by @goodb .

Will change model ID generation code, which currently grabs a random UUID, to instead simply use the model gene's identifier (e.g. WB:WBGene00003167, MGI:MGI:2159711).

Example model ID: gomodel:WB:WBGene00003167

That extra colon might wreak some havoc so the actual model ID pattern could change. This will help with keeping static URLs to test models after multiple iterations of generating models.