User defined signaling server

[roymckenzie]

Right now, HealthRecord supports y-webrtc and y-indexeddb Yjs connection and database providers for syncing data. Syncing works with the local IndexedDB fine, but only works between browser tabs right now through WebRTC due to an empty list of public signaling servers in the initialization of the WebrtcProvider. The public signaling server set as default in y-webrtc is not functional (yjs/y-webrtc#43) and to save browser resources attempting to connect to an unavailable WebSocket server for signaling, an empty list was set in this project.

I have created a new repo (y-webrtc-signaler) that includes a signaling server built for y-webrtc signaling that is easily deployable to cloud hosting providers including Heroku, Render, and Google Cloud.

A user should be able to choose which signaling server they would like to connect to and have their preference saved in their record's configuration settings when they download their record. A toggle in Settings could be created to enable WebRTC syncing with a text box that is revealed to allow a custom signaling server URL to be set. Optionally, if this project can sustain its own signaling server, provide another toggle that will enable the use of the project maintained signaling server.