Knowing the origin of an installed plugin

[judge2020]

Currently, I cannot seem to figure out a way to know the origin of an installed plugin for HDT. It is crucial to know where it came from so we can know the current version vs the old version and to remove them from the "available" plugin list.

A possible solution is to add a field to PluginManager that is the API URL and have manually installed plugins not include the field. Probably the best way.

Another possible solution it to require the plugin creators to include the API link as a field of IPlugin, however, that may be asking too much of creators. There are also many plugins which work but are not frequently updated/abandoned, which would prevent them from being on the list.