Add support for scanning and cleaning up plugins

[Kidbull]

This plugin is really nice and it would be awesome if it also supported cleaning up plugins

[ashe23]

I would be happy to implement that in a plugin, but there are a couple of challenges associated with cleaning assets in a plugin.

Currently, my method for detecting unused assets in a project is primarily based on the usage of primary or level assets. This means that primary assets and all their related dependencies are marked as 'used' and are never touched.

However, when it comes to plugin assets, there can be non-primary assets that are intended for use in any project. I'm facing a dilemma in determining whether such assets are unused or not.

I would greatly appreciate any proposals or suggestions regarding this issue.

I will categorize this issue as 'research,' allowing others to provide their suggestions if they have any.