Get minimal POC working

crates/rpc/src/proto.rs

@@ -99,6 +99,8 @@ messages!(
     (GetChannelsResponse, Foreground),
     (GetCodeActions, Background),
     (GetCodeActionsResponse, Background),
+    (GetHover, Background),
+    (GetHoverResponse, Background),
     (GetCompletions, Background),
     (GetCompletionsResponse, Background),
     (GetDefinition, Background),
@@ -175,6 +177,7 @@ request_messages!(
     (GetChannelMessages, GetChannelMessagesResponse),
     (GetChannels, GetChannelsResponse),
     (GetCodeActions, GetCodeActionsResponse),
+    (GetHover, GetHoverResponse),
     (GetCompletions, GetCompletionsResponse),
     (GetDefinition, GetDefinitionResponse),
     (GetDocumentHighlights, GetDocumentHighlightsResponse),
@@ -221,6 +224,7 @@ entity_messages!(
     GetCompletions,
     GetDefinition,
     GetDocumentHighlights,
+    GetHover,
     GetReferences,
     GetProjectSymbols,
     JoinProject,