Log VertexAI custom job URL

[EmilRex]

Logs the VertexAI Job URL for convenient access. Changes are sourced from the Prefect 1 implementation.

TODO

• Add tests
• Update CHANGELOG.md

Checklist

• References any related issue by including "Closes #" or "Closes ".
  • If no issue exists and your change is not a small fix, please create an issue first.
• Includes tests or only affects documentation.
• Passes pre-commit checks.
  • Run pre-commit install && pre-commit run --all locally for formatting and linting.
• Includes screenshots of documentation updates.
  • Run mkdocs serve view documentation locally.
• Summarizes PR's changes in CHANGELOG.md

[EmilRex]

I think this is best implemented as part of #206