### Godot version

v4.2.beta1.official [b1371806a]

### System information

Godot v4.2.beta1 - macOS 12.7.0 - Vulkan (Forward+) - dedicated AMD Radeon HD - FirePro D300 - Intel(R) Xeon(R) CPU E5-1620 v2 @ 3.70GHz (8 Threads)

### Issue description

When creating a plugin with a dot in the name in the project settings and leaving "Script Name" empty fails. Also, when a plugin folder is added via file system which contains a dot, information for that plugin cannot be be updated in the project settings.

Will be solved by: https://github.com/godotengine/godot/pull/83329

### Steps to reproduce

Create new plugin:

- Open project settings
- Click on "Create New Plugin" in the "Plugin" tab
- Choose a name with a dot in it (e.g., "my.plugin") and leave "Script Name" empty
- Create
- It will fail to create the plugin script

Update existing plugin:

- Add a plugin directory with a dot in the folder name (e.g., "my.plugin") in the file system
- Open project settings
- Click on the edit button in the "Plugin" tab for that plugin
- Change "Author" to some name
- Update
- Author was not changed in the table or in "plugin.cfg"

### Minimal reproduction project

[plugin_config_dialog.zip](https://github.com/godotengine/godot/files/12905755/plugin_config_dialog.zip)

if (p_config_path.length()) {
		Ref<ConfigFile> cf = memnew(ConfigFile);
		Error err = cf->load(p_config_path);
		ERR_FAIL_COND_MSG(err != OK, "Cannot load config file from path '" + p_config_path + "'.");
		name_edit->set_text(cf->get_value("plugin", "name", ""));
		subfolder_edit->set_text(p_config_path.get_base_dir().get_basename().get_file());
		desc_edit->set_text(cf->get_value("plugin", "description", ""));
		author_edit->set_text(cf->get_value("plugin", "author", ""));
		version_edit->set_text(cf->get_value("plugin", "version", ""));
		script_edit->set_text(cf->get_value("plugin", "script", ""));
		_edit_mode = true;
		active_edit->hide();
		Object::cast_to<Label>(active_edit->get_parent()->get_child(active_edit->get_index() - 1))->hide();
		subfolder_edit->hide();
		Object::cast_to<Label>(subfolder_edit->get_parent()->get_child(subfolder_edit->get_index() - 1))->hide();
		set_title(TTR("Edit a Plugin"));
	} else {
		_clear_fields();
		_edit_mode = false;
		active_edit->show();
		Object::cast_to<Label>(active_edit->get_parent()->get_child(active_edit->get_index() - 1))->show();
		subfolder_edit->show();
		Object::cast_to<Label>(subfolder_edit->get_parent()->get_child(subfolder_edit->get_index() - 1))->show();
		set_title(TTR("Create a Plugin"));
	}
	validation_panel->update();
	get_ok_button()->set_disabled(!_edit_mode);
	set_ok_button_text(_edit_mode ? TTR("Update") : TTR("Create"));
}
void PluginConfigDialog::_bind_methods() {