Rename DagRun queue state to avoid confusion with TaskInstance
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.
+1 providing that we handle API backwards compatibility well
When the task is waiting for worker it is also "didn't even start" in terms of operator execution.
In my experience it is always tricky to get the logic of scheduled/queued TI for the new people, but there was no problems with the DagRun states naming.
What would be the new proposed name for this state? "Pending"? This issue doesn't contain any mentions about the new name, and it is not clear would it hurt the UX much without it.
Pending sounds reasonable to me.
Is this issue only about renaming the state in UI? I have not worked on any UI-related issues before. Could I take a stab at this?
The name “queued” actually comes from the backend, but I think we could make this a UI-only change to avoid needlessly spending time migrating the database. Or at least we can make the UI change now and modify the backend later.
Yeah it shouldn't be hard to change any instance of dagrun queued to pending. We may want a new color too, no?
Or at least we can make the UI change now and modify the backend later.
Now that Airflow 3 is on the table maybe we should reconsider do both together?