Add the dca-template-config.json to this repo and use for testing

[anngvu]

Will likely bundle this with the next data model update, similarly to GF's PR here:

In this Slack announcement, D&T announced that we can maintain the templates config.json somewhere and DCA will reference the link (probably because keeping on top of PRs to update configs for 10+ DCCs is a lot of work):

For the next release of DCA in mid-December we are going to switch to new config files
...
the template dropdown config and logo will be referenced by a URL, not the filepath in data_curator_config. This means those files can live elsewhere, like your data model repo.