Batch add recipes

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

From time to time I find some recipes I want to add to the app's storage. Typically this happens in batches as if I start to dig into some recipe databases, I do find quite some recipes I find interesting.
I now have to add all the recipes URL by URL waiting for the cloud to fetch and store the relevant data until I can enter the next URL.

Describe the solution you'd like
I would like to have an option to enter a list of URLs (textarea). This should then be parsed line by line and imported as best as it can do now.
To avoid issues with timeouts, I suggest to simply do this on the client side. So a small JS script reads the textarea line by line and calls AJAX requests just as in the current implementation for the single-URL import. From the server side no change is needed. It is merely a UX issue with a small script to automate it.

Describe alternatives you've considered
Except for manually adding the recipes, I have not had a good idea. Maybe, one could use a local file + a bash script calling a series of curl invocations to simulate the REST calls but that's all I could think of at the moment.

Start with the existing single-URL import interface and its client-side AJAX request, then trace how the textarea and REST calls are wired. Add a textarea workflow that processes one URL per line using the existing import behavior; done means multiple recipe URLs can be submitted without waiting for manual entry between them.