Publish Dataproc Serverless Batch link after it starts if batch_id was provided

[rafalh]

Currently the link to Dataproc Serverless Batch is only available after its successful execution.
To improve user experience publish a link right after the batch starts execution if batch_id was provided. It makes it easier to observe the progress and find batch logs when it fails.
The only drawback is that if batch creation fails before it starts execution, the link will point to nowhere, but I think it is acceptable considering the gains.

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[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed in 5 days if no further activity occurs. Thank you for your contributions.

[rafalh]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed in 5 days if no further activity occurs. Thank you for your contributions.

Please unstale. Hopefully in thousand years someone will look into it...

[shahar1]

Sometimes we might oversee PRs - in that case, you could always ping us at the #new-contributors channel on Slack.
I had some minor comments, and I'd be happy if you could add/update a relevant test.
Thank you!

[eladkal]

@rafalh can you address comments and resolve conflicts?

[rafalh]

Sorry for the delay. I resolved the conflicts and I think it is ready for re-review.