Allow for graceful handling of padding on link title and url

Problem/Motivation

Links do not trim values before running validation.

Steps to reproduce

• Apply the change from https://www.drupal.org/node/3010895 → (https://git.drupalcode.org/project/drupal/-/merge_requests/6286/diffs.diff) to the codebase.
• Create a node bundle with an optional link field with required link text.
• Create a new node of this bundle, add a space to the URL field.
• Save the node.

Proposed resolution

trim contents of url and title fields