### 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)

return subfolder_edit->get_text().is_empty() ? name_edit->get_text().replace(" ", "_").to_lower() : subfolder_edit->get_text();
}
String PluginConfigDialog::_to_absolute_plugin_path(const String &p_plugin_name) {
	return "res://addons/" + p_plugin_name + "/plugin.cfg";
}
void PluginConfigDialog::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_VISIBILITY_CHANGED: {
			if (is_visible()) {
				name_edit->grab_focus();
			}
		} break;
		case NOTIFICATION_READY: {
			connect("confirmed", callable_mp(this, &PluginConfigDialog::_on_confirmed));
			get_cancel_button()->connect("pressed", callable_mp(this, &PluginConfigDialog::_on_canceled));
		} break;
	}
}
void PluginConfigDialog::config(const String &p_config_path) {