AIP-72: Implement short circuit and branch operators

[shahar1]

closes: #45823
related: #44912

Update: issue #43883 (Short Circuit for mapped operators) will be closed in a separate PR.

TODOS:

• Implement ShortCircuitOperator (including decorators)
• Implement BaseBranchOperator, BranchPythonOperator
• Fix core unit tests
• Fix tests of of BranchSQLOperator
• Fix tests of standard branch operators (within the standard provider)
• Add new core unit tests
• Relocate relevant modules to the standard provider

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Verified by running some of the example DAGs:

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Known Issues:

• Branching in Mapped Task Groups does not work. So the issue mentioned in BranchPythonOperator skips downstream tasks for all mapped instances in TaskGroup mapping #30883 is back. We will handle that in a separate PR.
• Get BranchExternalPythonOperator with Task SDK #47854

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[kaxil]

Known Issue:

Branching in Mapped Task Groups does not work. So the issue mentioned in #30883 is back. We will handle that in a separate PR.

[kaxil]

Added one more known issue to the PR description and added some screenshots

[kaxil]

We should be finally good to go on this!!

Waiting for the CI 🤞

[kaxil]

CI passed: https://github.com/apache/airflow/actions/runs/13866617491/job/38807327529?pr=46584

The static checks with providers was fixed in the last commit

[kaxil]

@shahar1 and I will fix any teething issues if something fails -- but we wanted to get it in since it is already too big and has been out for a while.