[MM-40638] Type all of the websocket event names as a new type WebsocketEventType (#25454)

Co-authored-by: Sudheer Tripathi <sudheer@clearglass.com>
Co-authored-by: Sudheer Tripathi <31629433+sudheer121@users.noreply.github.com>
Co-authored-by: Sudheer Tripathi <tripathisudheer604@gmail.com>

server/channels/app/reaction.go

@@ -137,7 +137,7 @@ func (a *App) DeleteReactionForPost(c request.CTX, reaction *model.Reaction) *mo
 	return nil
 }
 
-func (a *App) sendReactionEvent(event string, reaction *model.Reaction, post *model.Post) {
+func (a *App) sendReactionEvent(event model.WebsocketEventType, reaction *model.Reaction, post *model.Post) {
 	// send out that a reaction has been added/removed
 	message := model.NewWebSocketEvent(event, "", post.ChannelId, "", nil, "")
 	reactionJSON, err := json.Marshal(reaction)