Add more context

[rullzer]

See: https://docs.sentry.io/clientdev/interfaces/contexts/

We could add for example device info better. So we can identify the clients with versions etc.

[rullzer]

We should also try to parse the user agent string properly.

That way we can set if this is the desktop, android, ios client. Possible the OS (desktop). And the version of the clients.

Should help in finding out if certain clients do bad things.

[tcitworld]

Most of this is already detected by the Sentry SDK.