feat: add Plugins module with base files for plugins architecture

.gitignore

app/Config/Autoload.php

ecs.php

modules/Plugins/BasePlugin.php

modules/Plugins/Commands/InstallCommand.php

modules/Plugins/Config/Plugins.php

modules/Plugins/Config/Routes.php

modules/Plugins/Config/Services.php

modules/Plugins/Controllers/PluginController.php

modules/Plugins/PluginInterface.php

modules/Plugins/Plugins.php

phpstan.neon

plugins/.gitkeep