Batch creation UI

[mattias-p]

Depends on:

• Batch result UI #460
• Anonymous batch creation zonemaster-backend#1153

We should have a batch creation page. The page should have a text field accepting a list of space separated domain names and a submit button. If the creation request returns an error response, the error messages should be fed back to the user. If the creation request returns a successful response, the user agent should be redirected to the corresponding batch result page.

The GUI should have a configuration parameter to enable/disable the batch creation UI.

N.B. This is my interpretation of what we came up with at the F2F in January 2024.