[FR]: Group categories when an opml file is imported

[vicproj]

Brief description of the feature request

Hello,

First, thank you for developing and supporting this very good software. I recommend it to everyone.

I often generate my own OPML file (with multiple categories and feeds) and then import it in RSS Guard to update my feeds list.
When file is imported, all categories are duplicated (empty category is created if all feeds already exist, otherwise new category with new feeds is created) After I need to move manually feeds to existing categories and remove created ones.
Is there an option to reuse existing categories instead of creating new ones when an OPML file is imported ?

Thanks. Best regards.

Here is a screenshot of OPML import result (with updated feeds list) :