Hiding loose stone/boulders

[ong-yinggao98]

A script to hide all stone that isn't in its stockpile could clean up a lot of visual clutter and also help with cases when items get obscured by loose stone, the latter scenario making it unfeasible to just paint a hide command over an area lest it also hides furniture etc.

Some ideas as to how it could work:

• Have an aggressive option to auto-hide all stone when it is immediately produced (complements autostart)
• Be manually invoked to hide all previously unhidden stones since the last invocation
• Can selectively hide or unhide by stone type (ideally would apply to the autostart setting)
• Automatically unhide boulders destined for stockpiles or placed in stockpiles

Players can just use the vanilla menu to temporarily reveal all hidden stones.

[myk002]

except for the automation, this should be implemented by https://github.com/DFHack/scripts/pull/896