Adjust soil from digging to match construction needs

[chaosvolt]

Summary

SUMMARY: Balance "Increase soil yield from digging back up to an amount more in line with construction demand, belated sanity-checking for bashing rammed earth walls"

Purpose of change

When I sanity-checked digging I also reduced how much soil is produced by digging, but I'd overtuned it quite a bit compared to how much soil is used in the construction recipes I'd touched shortly before that.

Along the way, Royalfox on the BN discord pointed out that I forgot to adjust how much soil rammed earth walls give when smashed too, making them give more than they take to make.

Describe the solution

1. In iuse.cpp, changed digging_moves_and_byproducts so that it produces a total of 600 liters of material when excavated, for a maximum of 120 soil per deep pit. This works with rammed earth walls taking 100 soil and earthbag walls taking 108 soil.
2. Set rammed earth walls to give 50-75 soil when bashed.

Describe alternatives you've considered

Reducing soil demand in construction even more instead.

Testing

1. Compiled and load-tested.
2. Dug a deep pit, confirmed that it spawned over 100 soil altogether.

Additional context

Side note, boulders got a buff to how much stone they produce but solid rock didn't, I'll likely open another PR aimed towards giving a similar parity to obtaining rocks for stone walls.

[scarf005]

LGTM