[homekit] persist all known accessories, to prevent loss of homekit information ...

[homekit] persist all known accessories, to prevent loss of homekit information (#13484)

* [homekit] persist all known accessories, to prevent loss of homekit information

See the readme for more details, but basically this keeps track of every
accessory we've ever created, and if it no longer exists, presents a dummy
accessory instead. If the accessory comes back, nothing is lost in the Home
app; if you meant to prune it permanently, you have to run a console command.

there are also several fixes to prevent presenting the device with missing data -
such as when the bundle stops, _don't_ explicitly remove the accessories until
the server has stopped.

we also don't increment the configuration version unless the configuration
has _actually_ changed (so removing and re-adding the exact same thing
won't trigger the device to reconnect). this even works across restarts
of the bundle, because we're persisting all the accessory information
for dummy information anyway.

* [homekit] Address review comments for accessory persistence

* update hap-java to 2.0.4
* remove unused local variable
* [homekit] ensure accessories are replaced in a batch

so that HAP-Java can maintain subscriptions with the new objects

* [homekit] log individual dummy accessories up to 5
* [homekit] Tweak readme for dummy accessories slightly.

 * Be consistent with proper usage of useDummyAccessories.
 * Make the sentence more clear about the effects of having dummy accessories.

Signed-off-by: Cody Cutrer <cody@cutrer.us>