Rename DagRun queue state to avoid confusion with TaskInstance

[eladkal]

Body

Currently both DagRun and TaskInstance use queue as state (which is not related one to another at all)

I find that this is very confusing! because Queue DagRun actually means that the DagRun didn’t even start while queue task means it passed the scheduler and waiting for worker slot.

My suggestion simply not to use the same string (queue) to describe the different meaning.

(*) We also use Running for both DagRuns/tasks but I find this specific one less confusing as it actually means quite the same (something in worker is being executed).

Slack thread: https://apache-airflow.slack.com/archives/CCPRP7943/p1653990216805099

Committer

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