Add API functions to start and stop local Monero node

[duriancrepe]

Implemented a gRPC service GrpcMoneroNodeService which calls into CoreMoneroNodeService to start and stop a local monero node. The last successfully started local settings are are persisted and loaded on startup. The CoreMoneroNodeService attempts to connect to a local but externally started daemon process first, then looks for the last MoneroNodeSettings to start the local Monero node process with.

CoreMoneroConnectionsService is modified to accept the local Moner daemon which is connected to or started by the CoreMoneroNodeService. I've also included a small change to KeyStorage which fixes a Java String equality issue when investigating encryption requirements.

Resolves Issue #137

[woodser]

I don't see a need for CoreMoneroConnectionsService to be modified as part of this change to start and stop a local Monero node. CoreMoneroConnectionsService is an independent service to track and manage daemon connections. The local node is just another connection which may go online or offline.

If we want to automatically switch to the local node when the user starts it (could make sense), this can be supported by CoreMoneroNodeService starting the node and then manually setting the connection on CoreMoneroConnectionsService.

Update per my other comment: maybe the only warranted change to CoreMoneroConnectionsService is to automatically start the local node during initialization iff it was used last and is offline.

[duriancrepe]

I was able to decouple the two services by replacing the daemon's external interface to pick the local monero daemon's instance if it had started, see getPreferredDaemon.

I removed an unnecessary call to updateDaemonInfo during initialization since it is done on a timer and could be incorrect since the local node has not started yet. Finally, I added the startMoneroNode of CoreMoneroNodeService at the end of CoreMoneroConnectionsService's initialization in case the user had last started a local node (indicating preference to continue using the local node).

The local node setting and daemon is cleared when stopMoneroNode is called, and CoreMoneroConnectionService will provided the daemon connection as before. This allows the front end test to be simplified since we no longer have to track the additional local node "connection".

I think these changes to CoreMoneroConnectionService are unavoidable, since it provides the interface to access the daemon for the rest of the application via getDaemon.

[woodser]

See my other comments, but overall we want something like this:

The connection service and the node service are completely decoupled. The only interaction between them is:

1. the connection service, as a last step in initializing, starts the local node if it was last used and is now offline.
2. the connection service is registered as a listener on the node service. onNodeStarted(daemon), the connection service calls setConnection(daemon.getRpcConnection()), and onNodeStopped(), the connection service calls checkConnection() to update itself.

MoneroNodeSettings should always be present, defaulting to blanks.

Stopping the node should not clear the previously used node settings.

[duriancrepe]

Thanks for the detailed explanation, I think I finally get it.

One issue was that I had to add the hard coded password in the local monero node order to match the connection otherwise once you switch to a local monero node, it becomes persisted and you cannot restore the original hard coded connection with username and password. Efforts to restore the original hard coded value were difficult because the connection manager doesn't allow setting connection unless the node actually responded (the external monero process would be offline during the test).

[woodser]

Great. Please squash. I'm going to submit a commit on top to tweak some things.

[duriancrepe]

Great. Please squash. I'm going to submit a commit on top to tweak some things.

Squashed

[woodser]

I opened PRs on your branches for review. Thanks.

duriancrepe#4
duriancrepe/haveno-ts#5

[duriancrepe]

I opened PRs on your branches for review. Thanks.

duriancrepe#4 duriancrepe/haveno-ui-poc#5

Reviewed and merged in. Reran local monero node tests and confirmed working.