Multiple Redirects to respective URLs at the same time

Problem/Motivation

Currently, the user can add a single redirect - one at a time. When there are a lot of redirects to be done, it becomes a tedious task to do them one by one. On top of that, when a redirect is added successfully, the admin/config/search/redirect opens up, needing the user to again click on "Add Redirect" to again add a new redirect.

Steps to reproduce

1. Go to /admin/config/search/redirect and click on the "Add Redirect" button.
2. Add a redirect (any kind of redirect will do).
3. Click on "Save" button.

Proposed resolution

Add functionality - There will be a single "From - To" row to add a single redirect. However, at the bottom of it, above the "Save" button, there will be an option to add Redirect - "+ Add Redirect" which upon clicking will add another row for users to add another set of redirect with its' own Redirect status. And all other existing functionalities will work the same.

Remaining tasks

How the listing page will work when multiple redirects are being added at the same time is something that needs further discussion.

User interface changes

"+ Add Redirect" will be added in /admin/config/search/redirect/add page above the "Save" button for users to be able to add multiple redirects at the same time.

API changes

None.

Data model changes