Add ~feedback type label

What does this MR do?

Add new type label to capture feedback.

There are issues that don't fall into any of the existing type labels feature ~bug tooling support request meta documentation, but still contain useful information in the form of product feedback. Often this takes the form of an unintuitive product feature, or a misunderstood feature.

This MR proposes a new ~feedback label. There is an existing label Product Feedback which could also be used.

The ~feedback issues should eventually be routed to product managers.

Example of such issue:

• https://gitlab.com/gitlab-org/gitlab/-/issues/324770 - issue reported as bug, but it was a misunderstood feature. It's not very intuitive as 1d is converted to 8h, instead of 24h.