[AIP-94] airflowctl command migration

[bugraoz93]

Body

Goal: move every remote airflow CLI command (anything backed by a public REST API endpoint)
into airflowctl. Admin commands have no API and are local-only. They run components (scheduler,
api-server, triggerer, dag-processor, kerberos, standalone), manage the DB, or reach internals
directly (DAG parsing/rendering, local provider manager). Those remain in the airflow CLI and are
out of scope here.

Why:
AIP-81: Enhanced Security in CLI via Integration of API
and its sub-proposal
AIP-94: Decouple Remote Commands from the airflow CLI.

Status: converted. The only work per command now is to add the marker decorator to the
listed commands so they are frozen for development. There is no airflowctl migration to
do.

What to do:

• Add the marker decorator to each command on the list. See PR Convert CLI Deprecations to maintainer idetifiable only #68726 for how the
  decorator is converted to a maintainer and developer facing marker (it replaces the
  user facing deprecation warning). Apply that same decorator to each command.
• The decorator is maintainer and developer facing only. It records the airflowctl
  equivalent and adds a note in the code, and it does not print anything to users or
  change behavior.
• The point of the marker is to freeze these commands for development. Once a command is
  marked, no new features or behavior changes should land on it.

Admin (no API, local-only, not migrated, stay in the airflow CLI):

• dags: show, show-dependencies, test, reserialize (parse/render DAGs directly)
• tasks: test, render (execute/render DAG files directly)
• providers: links, widgets, hooks, triggers, behaviours, logging, secrets,
  executors, queues, notifications, configs, lazy-loaded, auth-managers (read the local
  provider manager)

dags

• dags trigger ([AIP-94] Create a CLI airflowctl client and adopt it in existing commands #68175)
• dags delete ([AIP-94] Create a CLI airflowctl client and adopt it in existing commands #68175)
• dags list
• dags details
• dags state
• dags list-runs
• dags list-jobs
• dags list-import-errors
• dags report
• dags clear
• dags pause
• dags unpause
• dags next-execution

tasks

• operations for tasks ([AIP-94] airflowctl tasks: add TasksOperations and TaskInstancesOperations to operations.py #66173)
• tasks state (depends on [AIP-94] airflowctl tasks: add TasksOperations and TaskInstancesOperations to operations.py #66173)
• tasks states-for-dag-run (depends on [AIP-94] airflowctl tasks: add TasksOperations and TaskInstancesOperations to operations.py #66173)
• tasks clear (depends on [AIP-94] airflowctl tasks: add TasksOperations and TaskInstancesOperations to operations.py #66173)
• tasks list (depends on [AIP-94] airflowctl tasks: add TasksOperations and TaskInstancesOperations to operations.py #66173)
• tasks failed-deps (depends on [AIP-94] airflowctl tasks: add TasksOperations and TaskInstancesOperations to operations.py #66173)

assets

• assets materialize ([AIP-94] Create a CLI airflowctl client and adopt it in existing commands #68175)
• assets list
• assets details

pools

• pools: list / get / set / delete / import / export ([AIP-94] Create a CLI airflowctl client and adopt it in existing commands #68175)

variables

• variables list
• variables get
• variables set
• variables delete
• variables import

connections

• connections list
• connections add
• connections delete
• connections import
• connections test
• connections create-default-connections

backfill

• backfill create

jobs

• jobs check

config

• config get-value
• config list

providers

• providers list
• providers get

Committer

• I acknowledge that I am a maintainer/committer of the Apache Airflow project.

[Prab-27]

I'm working on connections