Support method names, that contain periods

[ccb23]

jsonrpc_client! macro does not work with method names form kodi API. Kodi API uses dots in its methods: e.g. AudioLibrary.GetSongDetails. As far as I understand this should be JSON RPC 2.0 spec conform.

[pronebird]

I am not entirely sure it's possible to achieve without adding some attributes, which would be neat!

However, you can build the RPC client without using the jsonrpc_client! macro. See how we do that in our IPC client: https://github.com/mullvad/mullvadvpn-app/blob/master/mullvad-ipc-client/src/lib.rs#L118