Fix "Add data" button width for some languages.

[glughi]

What this PR does

Fixes #7726

Checklist

• There are unit tests to verify my changes are correct or unit tests aren't applicable (if so, write quick reason why unit tests don't exist)
• I've updated relevant documentation in doc/.
• I've updated CHANGES.md with what I changed.
• I've provided instructions in the PR description on how to test this PR.

[zoran995]

Hi @glughi thanks for finding this. Can we completely remove the fixed width from this button and use something as

• url input wrapper - flex layout
• url input text box - height auto, width: 100%
• url input add button - width unset; max-width: 150px; word-wrap: break-word;

This way, any text length should work

[zoran995]

lgtm

[niktayv]

I tested it, and everything worked well.
The code changes LGTM, save for a couple of nitpicks.