Graph API supports bi-directional updates for Releases (Playnite Game…

…s) (#711)

Playnite Web Releases can have certain properties updated via the Graph
API that will reflect in both Playnite and Playnite Web.

> Note that relational properties must be handled individually for every
entity type in Playnite. Currently this PR enables the Graph API to
support Playnite Games' features. Soon to be included completion status,
too. Others will be considered additional features and will have a
dedicated issue for each.
> Note this does not enable a UI to support updating data. This will be
handled in a future PR.

The following cases are handled:

- [x] Sending an update to the Graph API for non-relational properties
and Playnite is running, then the update is applied to Playnite.
- [x] Updates applied to Playnite via the Graph API for non-relational
properties, will synchronizec back to Playnite Web automatically when
successfully updating Playnite.
- [x] One or more updates are sent to the Graph API, while Playnite is
not running. Each update is applied in chronological order once Playnite
comes back online.
- [x] Graph API provides a subscription for entity updates. When an
entity is updated from Playnite, subscribers are notified of the change.
This allows automatically updating the UI with fresh data.
- [x] Playnite game features relational property is supported for
updates (add and remove)
- [x] duplicated adds and removes are ignored
- [x] adds or removes with invalid Oids are ignored

Closes #569 
Closes #696 
Relates to #461 

BREAKING CHANGE - MQTT update messages have changed. The message topic
taxonomy, payload shape, and persistence have changed. Update and
connection messages are not persistent. Bi-directional updates rely on
persistent message in MQTT. Please see the setup documentation for an
example Mosquitto configuration file to enable persistence. Please see
MQTT documentation for changes to message formats.