[BUG] Trigger TV mode OFF in a homekit scene causes double IR commands.
**Describe the bug**
I have a scene in homekit called 'goodnight' that turns every device in the house off.

When the TV device is already turned off in homekit, triggering this scene wil result in the harmony hub sending all the 'OFF' commands a second time (resulting in devices switching on)

**To Reproduce**
- Create a scene in homekit, add the TV device and let the scene trigger an 'off' state to the TvDevice. 
- Make sure no activities are running on the harmony hub and the Tv Device is off to begin with.
Run the scene.

**Expected behavior**
Triggering the off state a second time should not do anything if the tv device is already off.

**IOS (please complete the following information):**
- Version [12.2 public beta 6]
- Device: [iPhone XR]
- Plugin version 5.5 (Can't update via npm to 6.0 yet?)

**Logs**
[https://pastebin.com/TF4T4A4u]

**Config**
` {
   "platform": "HarmonyHubWebSocket",
    "name": "Woonkamer",
    "hubIP": "192.168.42.123",
    "TVPlatformMode" : true,
    "mainActivity" : "Apple Tv",
    "playPauseBehavior" : true,
    "showTurnOffActivity" : true,
    "publishActivitiesAsIndividualAccessories" : true
  }
   ]
 }
`
**Additional context**
I tried to overcome this problem by adding the "showTurnOffActivity" parameter but this seems to be broken for me, I can't get an all-off button to appear in homekit.. tried rebooting everything, re-adding homebridge to homekit etc. 
Does this only work when "TVPlatformMode"  is set to false?
[https://pastebin.com/KSL7e1Vt]
