rpcclient: Client doesn't expose any of the 'stopnotify*' JSON-RPC commands

[jordansaints]

As best as I can tell, all 4 of the stopnotify* JSON-RPC commands (e.g. stopnotifyblocks), though implemented in btcjson a long time back (#342), are not currently exposed as methods on the rpcclient.Client. If these commands are meant to be in line with their notify* counterparts (e.g. notifyBlocks) as the json_rpc_api.md documentation suggests, then I believe these method implementations are missing.

Is there a way to access that functionality that I am overlooking? Maybe there is a manual way to issue the RPC command using btcjson? The docs and examples given all seem to indicate that that method should be defined as part of the Client struct, probably in rpcclient/notify.go alongside NotifyBlocks() etc. Thoughts?

I see that the coming gRPC API (#1075) will expose this functionality as well, but as there is no clear timeline of when that will ship, exposing this method through the existing websocket RPC API would be ideal.

I would love to know if I am missing something here, or if not, I would be happy to open up a PR and attempt a fix. Thanks for your help! 🙂