Return GCS URIs from GoogleAdsToGcsOperator for Issue #11323

[Abhishekmishra2808]

PR Update

• Update GoogleAdsToGcsOperator.execute() return type from None to list[str]
• Return a list containing the full gs:// URI of the uploaded GCS object
• Add docstring documentation for the new return value
• Update unit tests to validate the returned GCS URI format
• Fix test BUCKET constant by removing the gs:// prefix

Related: #11323

[shahar1]

You're in the way, but there's some work to so :)
Also, please fix static checks using prek (instructions are available in the docs)

[shahar1]

1. In a second thought, I now wonder whether we should introduce the unwrap_single parameter at all, as it already returns the expected result (list[str]). It could be a nice feature for the while, at least until we align the rest of the operators.
   I'll be happy for more opinions, for now I keep it as is.

2. Following a recent incident, I'd rather merge this PR after ensuring that the system tests pass.
   @Abhishekmishra2808 if you're able to do so, I'll be happy if you could attach a screenshot that it runs succesfully for the modified operator. Otherwise, we'll wait for Google team or anyone else to run them.

CC: @VladaZakharova @MaksYermak