Add option in viewer to directly show a plugin page
Testing Done:
Ran `gplugin-gtk4-viewer -p gplugin/native-basic-plugin` and it opened the `basic plugin (C)` page directly.
Ran `gplugin-gtk4-viewer -p asfalskjf` and it exited with an error.
Reviewed at https://reviews.imfreedom.org/r/2148/
/*
* Copyright (C) 2022 Elliott Sales de Andrade <quantum.analyst@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <https://www.gnu.org/licenses/>.
*/
#include<glib/gi18n-lib.h>
#include<gplugin.h>
#include<gplugin-gtk-plugin-closures.h>
#include<gplugin-gtk-plugin-page.h>
#include<gplugin-gtk-plugin-settings-list.h>
#define G_SETTINGS_ENABLE_BACKEND
#include<gio/gsettingsbackend.h>
/**
* GPluginGtkPluginPage:
*
* A widget that displays a single [iface@GPlugin.Plugin] in a user friendly
* way, intended to be placed in a [class@GPluginGtk4.View].