fix: `DataType.prototype.getByVersionId` could return wrong type

[EvanHahn]

We have many DataTypes backed by the same DataStore. For example, observations and tracks are both in the "data" store.

DataType.prototype.getByVersionId would pull documents from the store without checking the type, which could cause issues. Simple code example:

const track = await trackDataType.create({ /* ... */ })

await observationDataType.getByVersionId(track.versionId)
// => the track, unexpectedly!

Now, it throws a NotFoundError.