Introduce sub environments

[Nostradamos]

Basically extend environments so that they can have a "parent" environment.
Think of a a mini greenhouse in your Growbox. It get's the same the light but
has different temperature/humidity value. It should be possible to retrieve all the sub environments of a parent environment.

{
  environmentId: 42,
  environmentName: "Mini greenhouse #1 in Growbox #1",
  environmentDescription: "This is my small greenhouse xyz placed in Growbox #1",
  ...
  environmentParent: 41,
  environmentParentJournalsAllow: ["light", "cycle"],
  environmentParentJournalsDisallow: ["rlf", "temp"]
}

{
  environmentId: 41,
  environmentName: "Growbox #1",
  environmentDescription: "This is my Growbox #1",
  ...
  environmentParent: null,
  environmentParentJournalsAllow: null,
  environmentParentJournalsDisallow: null,
  environmentSubs: [42]
}