Feature Request: Run import synchronously

[tricki]

I'm initiating imports from an external application (using the Feed URL), but I need to know when the import has finished.

Right now the import is run in a queue, making it impossible to tell when the import has finished from the request alone.

After a quick look through the code, I think this could be achieved by adding a new query param (e.g. sync=1) and running the import directly, without adding it to the queue:

https://github.com/craftcms/feed-me/blob/develop/src/controllers/FeedsController.php#L365-L372

In my case the import takes a long time (about 5 minutes), so the request timeout would need to be increased (if it isn't already).