Remove unused grass (seed) implementation from both client and N3ME.

[stevewgr]

Description

This pull request removes an unused grass (or seed) implementation from both the client and N3ME. This feature, referenced as "seed" in N3ME and "grass" in the client, is not utilized in the official game, making it unnecessary to maintain.

Details

• The grass/seed feature was never used in the official release, as verified by examining the Misc/grass files, which have remained unchanged since the game's initial release. It also seems like a work-in-progress implementation.
• Based on the code in both the client and N3ME, it appears the original developer had plans for this feature to integrate with terrain data (gtd). However, in the official implementation, grass and seeds were added as shapes in the opd file with basic textures and no collision, rather than being part of the terrain data.

Rationale

Given its lack of use and maintenance, removing this redundant implementation reduces complexity and potential confusion in the codebase. This change helps streamline development by eliminating an unused feature that provides no functional benefit.

[stevewgr]

@srmeier @xGuTeK thoughts?

For the record, build is passing: https://github.com/ko4life-net/ko/actions/runs/11809857978

but I'll still wait to hear your thoughts / review before merging.