TS Server: Send error event when a plugin fails to load

[mjbvz]

Problem
When a TS Server plug-in is not loaded, the TS Server currently fails silently. This results in a confusing experience for users since intellisense or other expected plugin features will not work. You currently have to check the TS Server logs to see that a plugin was not loaded

Request
Send an error event to the client when a plugin fails to load. I imagine the interface would look like:

type PluginInitializationFailedEventName = "pluginInitializationFailed";

interface PluginInitializationFailedEvent extends Event {
    event: PluginInitializationFailedEventName;
    body: PluginInitializationFailedEventBody;
}

interface PluginInitializationFailedEventBody {
    name: string;
    project?: string; // Path to the js/tsconfig file that registered this plugin
}

[mjbvz]

@DanielRosenwasser @minestarks I think we will want this for the IntelliCode plugin. Otherwise users will be very confused as to why the functionality may not working (especially since the plugin is an implementation detail that most users should not have to care about)