Bug fix UI crash when url is unrechable

[sorydi3]

Description

Issue:1577

• Implemented a check to verify if the domain is reachable before initiating the transformation. If the domain is not reachable, an exception is thrown.
• Added unit tests to verify the functionality of converting a website to PDF, including scenarios where the domain is not reachable.

Closes #(1577)

Before Changes:

After Changes:

Checklist:

• I have read the Contribution Guidelines
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings

Contributor License Agreement

By submitting this pull request, I acknowledge and agree that my contributions will be included in Stirling-PDF and that they can be relicensed in the future under the MPL 2.0 (Mozilla Public License Version 2.0) license.

(This does not change the general open-source nature of Stirling-PDF, simply moving from one license to another license)

[Frooodle]

Seems tests are failing in github

[sorydi3]

umm I'll take a look ,locally all test are passing thought. it is a bit strange.