Prep PR #9091 for Sprint

[mreekie]

• Extend 'metadatablocks/{block_id}' endpoint JSON output #9091

This issue is from

• The Dataverse Global Backlog
• The "SPRINT PREP" Column.
• There is a draft readme there that has additional information.

Our Objective is to get it into the "SPRINT READY" column

• Take a look at the SPRINT PREP column readme.
• Add the "Technical Tasks" Required Sections:"
• Fill them in.
• If there is anything already in the issue description
  just add a line i.e. --- at the top and put the required
  sections above what is already there. (No need to
  delete what is already there)
• The intent is that by thinking/talking through this in
  a bit of detail will lead to a better estimate of the
  size.
• Speaking of which, if a PR is well defined per the
  DV definition, then it likely can just be sized.