Add hidden wreck/heap metal modoption for tests

[efrec]

Work done

• Adds modoptions wreck_metal_ratio and heap_metal_ratio for testing reclaim amounts. Usage is !bset wreck_metal_ratio 0.5 for 50% of unit metal value.
• Does not rebalance build costs of eating/rezzing so the min/max modoption values are bounded semi sensibly.
• Adjusted the reclaim highlights widget slightly (square of the difference) to filter out minimum feature metal/energy based on the adjusted value.

Values for wreck_metal_ratio should be between 0.2 and 0.8 (default 0.6) (ish) given current game design. I don't think I've seen any pronouncements on heaps.

This was requested for balance testing by coordinators so should be considered temporary. I don't mind adding an end date to the modoption (since that's been discussed as a feature to implement) or waiting on that feature to add this.

This could be considered a cheat option, especially when increasing metal reclaim from Raptors, but I didn't see the point in moving it to the cheats section, personally.

[github-actions]

Test Results

14 tests  ±0   7 ✅ ±0   9s ⏱️ ±0s
 1 suites ±0   7 💤 ±0 
 1 files   ±0   0 ❌ ±0 

Results for commit 6072e51. ± Comparison against base commit ea60385.

♻️ This comment has been updated with latest results.

[efrec]

re: not respecting modoption limits, here's an 80x metal modifier

*edit: I've capped the multipliers to be non-cheaty.

[TheChronographer]

The other way to do this, to balance test specific units, could be adding a custom param of 'non uniform heap/wreck values' and then adding an exemption to the alldefs_post like commanders have.

Could be useful to allow 'raiding units' (e.g. blitz) donate less metal as a balance testing tool.

[efrec]

K this is much-simplified.

A tweaks approach will be a separate PR. I think we want to keep using these ratios and not allow them to become too arbitrary. But still there are things the coordinators will want to test per-unit.

[keithharvey]

LGTM