Import RSS feeds via OPML / CSV

[csolisr]

Is the feature request related to a problem? Please describe.

Friendica currently has the ability to follow RSS feeds, but not the ability to import them - neither as OPML files (to my knowledge, despite of the fact that there is an add-on already to export RSS feeds as OPML), nor as a CSV import file (as Friendica assumes all CSV imports to be ActivityPub-based, so the follow of a RSS feed fails).

Describe the feature you'd like

I would like the ability to manage the import of OPML files, or else to parse CSV imports as RSS feeds as a fallback from ActivityPub, or both.

Describe alternatives you've considered

I have already attempted to convert my OPML import file to a CSV list, which fails as described above.

Additional context

Currently using the latest development version of Friendica and its addons.

[csolisr]

See also the related issue #9510.