Improve refinement process

Why is this change being made?

We are trying to improve our refinement process in Package. Here is my proposal to further build on the MR Steve made to assign a refinement DRI.

Problem	Proposal
Issues are coming into the milestone unrefined	Use labels to better plan for refinement
Unclear what the process is when refinement results in new issues	Adds guidelines for refinement DRI
Product designer needs to pre-refine issues before engineering refinement begins (e.g. having informal conversations to scope technical feasibility), but should only focus on issues that are likely to be built to be efficient	Use labels for issues that need to be refined within the quarter that product designer can monitor
Randomly assigning refinement DRI not defined	😛 is this an opportunity to build a tiny app??

Author Checklist

• Provided a concise title for this Merge Request (MR)
• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what
  • Copy/paste the Slack conversation to document it for later, or upload screenshots. Verify that no confidential data is added.
• Assign reviewers for this MR to the correct Directly Responsible Individual/s (DRI)
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to one of the people listed in the Maintained by section on the page being edited
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• If the changes affect team members, or warrant an announcement in another way, please consider posting an update in #whats-happening-at-gitlab linking to this MR
  • If this is a change that directly impacts the majority of global team members, it should be a candidate for #company-fyi. Please work with internal communications and check the handbook for examples.

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