Add device_templates support to emulator-plugin

[lazypower]

As advertised on the tin.

We need to pass in configurations to the emulator, and we have a standard array of door/lock configurations that would be nice to templatize as a device_template.

Ideally the incoming configuration would be similar to this map as an example:

door_config: {r1: nine-door, r2: nine-door, r3: three-door, r4: three-door, r5: nine-door, r6: three-door}

That map results in a script consuming the map, and rendering configuration segments in /synse/plugin/config/ (Needs citation).

[lazypower]

I'm going to pull the assignee and good-first-issue label. I've dug into this over the last 2 days and it's not as straight forward of a problem domain as I'd like. There are other low-hanging items we can close out that wont require such an upfront investment in decoding a prior approach w/ assumptions.