MM-26056 Add plugin ability to execute slash command. (#14898)

* Add plugin ability to execute slash command.

* A test

* Add site url to command args for plugin API

* Remove unessiary complexity.

plugin/client_rpc_generated.go

@@ -523,6 +523,36 @@ func (s *apiRPCServer) UnregisterCommand(args *Z_UnregisterCommandArgs, returns
 	return nil
 }
 
+type Z_ExecuteSlashCommandArgs struct {
+	A *model.CommandArgs
+}
+
+type Z_ExecuteSlashCommandReturns struct {
+	A *model.CommandResponse
+	B error
+}
+
+func (g *apiRPCClient) ExecuteSlashCommand(commandArgs *model.CommandArgs) (*model.CommandResponse, error) {
+	_args := &Z_ExecuteSlashCommandArgs{commandArgs}
+	_returns := &Z_ExecuteSlashCommandReturns{}
+	if err := g.client.Call("Plugin.ExecuteSlashCommand", _args, _returns); err != nil {
+		log.Printf("RPC call to ExecuteSlashCommand API failed: %s", err.Error())
+	}
+	return _returns.A, _returns.B
+}
+
+func (s *apiRPCServer) ExecuteSlashCommand(args *Z_ExecuteSlashCommandArgs, returns *Z_ExecuteSlashCommandReturns) error {
+	if hook, ok := s.impl.(interface {
+		ExecuteSlashCommand(commandArgs *model.CommandArgs) (*model.CommandResponse, error)
+	}); ok {
+		returns.A, returns.B = hook.ExecuteSlashCommand(args.A)
+		returns.B = encodableError(returns.B)
+	} else {
+		return encodableError(fmt.Errorf("API ExecuteSlashCommand called but not implemented."))
+	}
+	return nil
+}
+
 type Z_GetSessionArgs struct {
 	A string
 }