Update app to load v3 definitions from new URL

[mattsacks]

Builds upon #13

[mattsacks]

I think this is already taken care of:

So going backwards from when we load the JSON, here you can see us getting a version of it:

app/src/utils/device-store.ts

Line 98 in ef8273d

const url = `/definitions/${version}/${vpid}.json`;

That vid is the requiredDefinitionVersion that is stored for the device:

app/src/store/definitionsSlice.ts

Line 217 in ef8273d

getMissingDefinition(device, requiredDefinitionVersion),

Which is loaded into the redux store based on it's protocol:

app/src/store/devicesThunks.ts

Line 107 in ef8273d

requiredDefinitionVersion: protocol >= 10 ? 'v3' : 'v2',

@olivia @ValdisThomann let me know that's wrong!

[ValdisThomann]

We need to test this.