Fix polling HomeKit devices with multiple services per accessory

[Jc2k]

Description:

While testing the new beta to see if #25249 helped with scaling and stability issues with many homekit entities @niemyjski reported seeing this traceback:

2019-08-01 07:54:51 ERROR (MainThread) [homeassistant.components.homekit_controller] Exception in async_state_changed when dispatching 'homekit_controller_43:0A:AB:59:F0:BC_state_updated': ()
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/homekit_controller/__init__.py", line 126, in async_state_changed
    char_name = escape_characteristic_name(self._char_names[iid])
KeyError: 66

HomeKit accessories are made up of Accessories, Services and Characteristics. Most of the devices i work with are either a single accessory with a single service or for a bridge like Hue, many accessories each with a single service. But there are also devices with many accessories and many services and also 1 accessory with many services. Sensors often have CO2, temperature and humidity as a single accessory with multiple services.

The code in #25249 didn't adequately consider these devices and failed when encountering a characteristic from another service on the same accessory. This PR handles that case.

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the [development checklist][dev-checklist]

[Jc2k]

Can this be go in 0.97.0 too as its a regression.

[MartinHjelmare]

Just a typo.