Issue labe improvements

[Peter Krempa]

Hi,

from time to time when I try to go through upstream issues I always feel
that the labels we have are suboptimal and don't always allow to track
the current state of the issue.

Recently I've had a look at the qemu issues and found what I was
lacking.

Specifically I'm lacking the 'workflow' class of labels they use.

I propose we adopt the following changes:

1) Convert the existing 'bug', 'enhancement', 'support', and
'discussion' labels into a set of scoped labels (again inspiration taken
from qemu):

 kind::bug
 kind::enhancement
 kind::support
 kind::discussion
 kind::documentation

This is mostly as the above kinds are mutually exclusive.


2) Introduce the workflow label similarly to what qemu uses:

 workflow::Confirmed/Triaged (<- confirmed for bugs, triaged for
                               enhancements)
 workflow::Needs Info (replaces "needinfo")
 workflow::In progress (replaces "Doing")

I'd also potentially like to have a 'Unconfirmed' state for when the
bug has enough info, but it's unknown why it's happening.

I want to specifically avoid the ambiguous "Triaged" when used on it's
own.

3) Convert host-* labels into a scoped label. Hosts are usually mutually
exclusive

4) Convert driver-* into scoped labels. Usually issues are not exceeding
these boundaries

5) Remove the following unused or ambiguous labels:

  - critical
  - incident
  - Doing
  - To Do
  - gsoc::20* (all seem to be unused)


I'm willing to go ahead and re-triage open stuff if nobody objects to
the above changes.