Update Structures

[cosmiccoincidence]

Summary

Updates structure files in current project.
This PR ports a few assets from the 'outdated' branch but does not add any new assets from the google drive.

Changes to Files

• Port floor textures from 'outdated' branch,
• Update floor materials and some prefabs,
• Add all floor tiles as tilemap objects,
• Add connection scripts to pipes and cables & added them as tilemap objects,
• Remove shadows from several structure prefabs

Notes

I did not add windows or wires because the window/wire connection scripts need to be written first and their design may change if we end up changing the tilemap connection setup to being offset as discussed on Discord.

[TaylorNAlbarnaz]

lgtm