Requisition de-bork batch

[Kubius]

[BUGFIX]

About the PR

Fixes two issues with requisition entry handling with some additions to the entry code and according changes in entries themselves.

• Adds an optional material ID parameter to the item stack entry; if defined, requires the provided material ID string to match one present on the stack. This is now used for steel sheet stack evaluation instead of the path, as the path isn't maintained when splitting sheet stacks. Much better.
• Adds and implements a new "food item" entry type that's aware of bites_left, now that that's a distinct thing from amount. Default behavior is to require initial bites_left on food (in other words: intact) and count per food item, but incrementing based on bites_left is also supported (currently used only for pizza, to allow slices).

Why's this needed?

Fixes #9809, #9889 and #13227.

Changelog

(u)Kubius
(+)Fixed some requisition handling goofs that could cause orders to fail, most notable in the handling of steel sheets for an aid contract.