Client: CommandValidator and initialRequest were added,fixed behaviour if server is unreachable; Server: GetCommandsCommand was added

server/src/main/kotlin/Main.kt

@@ -67,6 +67,7 @@ fun registerServerCommands(
         AddIfMaxCommand(manager),
         AddIfMinCommand(manager),
         HistoryCommand(invoker),
+        GetCommandsCommand(invoker),
         SumOfMinutesCommand(manager),
         MinByNameCommand(manager),
         PrintDescendingMinutesCommand(manager),

server/src/main/kotlin/commands/GetCommandsCommand.kt

@@ -0,0 +1,15 @@
+package commands
+
+import models.HumanBeing
+import runner.CommandInvoker
+
+class GetCommandsCommand (
+    private val invoker: CommandInvoker
+): Command {
+    override val name: String = "GetCommands"
+    override val description: String = "Получает все доступные с сервера команды"
+
+    override fun execute(args: List<String>, humanBeing: HumanBeing?): String {
+        return invoker.getCommands().toString()
+    }
+}