Increase visible size of Path and To fields

I filed this as a result of a real-life issue. Another staff member asked me to check why a particular redirect didn't seem to be having any effect. It turned out when they copied and pasted the path, they accidentally copied some additional text after the end of the path, causing the path not to match. It wasn't obvious because the full path ran past the end of the field.

Added the feature to make the fields "Path" and "To" to cover full width.
Please review.

I've reviewed the patch and the code looks good. I am running into problems figuring out how to run it in Simplytest.me, and will need to request help separately. I'll come back to this issue when I've resolved that.

Confirmed it works, including testing adding a redirect.

I'm not sure my review is sufficient, so leaving in Needs Review.