[RW-812] Fix external links for jobs/training

[orakili]

Refs: RW-812

This adds the target and rel attributes to external links to open in new tab for links inside fields using the markdown_editor (ckeditor 5) text format.

Tests.

1. Checkout the branch, clear the cache, import the config
2. Create or edit a job or training, add some links in the body starting with https://reliefweb.int and your local domain like https://rwint-local.test.
3. Add links to external sites
4. Save
5. Confirm that the RW (prod and local) links do not have a target and rel attributes
6. Confirm that the external links have those attributes and open in new tab/window

[github-actions]

Build output

Composer Validate success

PHP Lint success

Docker Build success

Environment Setup success

Site Install success

PHP Code Sniffer success

Software Versions

PHP 8.2.10 (cli) (built: Sep 2 2023 06:59:22) (NTS) Copyright (c) The PHP Group Zend Engine v4.2.10, Copyright (c) Zend Technologies with Zend OPcache v8.2.10, Copyright (c), by Zend Technologies with Xdebug v3.2.1, Copyright (c) 2002-2023, by Derick Rethans Composer version 2.6.3 2023-09-15 09:38:21

Drupal Logs

Pusher: @orakili, Action: pull_request, Workflow: Run tests

[github-actions]

Coverage Report

Totals
Statements:	11.76% ( 1092 / 9286 )
Methods:	11.72% ( 83 / 708 )
Lines:	11.76% ( 1009 / 8578 )

[left23]

Works as described.