inLineEdit - onSubmit function delivers empty values of hidden colums

inLineEdit - onSubmit function delivers empty values of hidden colums. That's very insidious and dangerous because it causes destroying of data in invisible columns.

I have following workaround:
` $this->hiddenColumns = $grid->getSessionData('_grid_hidden_columns');

    $grid->getInlineEdit()->onSubmit[] = function($id, $values) {
        $notHiddenValues = [];
        foreach ($values as $key => $value) {
            // zjistit je column hidden a vynechat ho
            if (empty($this->hiddenColumns) || (!in_array($key, $this->hiddenColumns, true))) {
                $notHiddenValues[$key] = $value;
            }
        }

        if ($this->db->table('cenik')->where('cenik_kod=?', $id)->update($notHiddenValues) !== false) {
            $this->logManager->recordTableUpdate('cenik', $notHiddenValues, $notHiddenValues,
                'cenik_kod', $id);
            $this->flashMessage('Ceníková položka byla uložena', self::MSG_SUCCESS);
        } else {
            $this->flashMessage('Chyba při uložení ceníkové položky', self::MSG_ERROR);
        }

        $this->redrawControl('headerSnippet');
    };

`

Start at the inline-edit onSubmit entry point mentioned in the issue and reproduce an edit while one or more columns are hidden. Trace which values are submitted and persisted, then verify that hidden columns are not replaced with empty values while visible edits still save correctly.