[manual squash] Update Bucket mod

[tenplus1]

Initial minetest. to core. tidy

Simplify: Early return checks, nil check, replace set_node air with remove_node (empty bucket).

Simplify2: Early return checks, nil check, default below position with check for above (filled bucket).

[sfan5]

My personal opinion is that we shouldn't be changing minetest to core in existing code. It's busywork.

[tenplus1]

@sfan5 - I'll only do it if actually changing the code within.

[sfan5]

But what did you actually change? The diff is huge and this is hard to review.

[tenplus1]

@sfan5 - The main changes were in the "Simplify" part above with some early returns set and redo of the force_renew, also using remove_node instead of setting to air.

[SmallJoker]

Looks good aside from the comments. The adjustments will need manual squashing. Otherwise it'll be very difficult to differentiate renaming vs restructuring changes.