(!1156) Refund construction

GR.org Link

Link to GameReplays if this merge requests needs discussion (also add "discussion label")

 

Description

Makes forts and wallhubs refundable at 95% during the first 6s of their lives (it takes about 3.5s for a builder to disappear)

 

Checklist

I have:

• Tagged my change with the ;,; comment block.
• Ensured that this merge request changes exactly one thing.
• Attached the proper labels to this merge request.
• Added the Merge Request number in the title. e.g. (!42)
• Added a devlog entry for this change.
• Tested my code.