Refactor builder store and remove wall store
- Consolidated wall-related state management into the builder store by removing the useWallStore.
- Added new properties and setters for wall attributes (thickness, height, materials) in the builder store.
- Introduced SelectedWallProperties and WallProperties components for managing wall properties in the sidebar.
- Created a new floor store for managing floor-related state.
- Added a wall asset store for managing wall assets.
- Implemented a zone store for managing zones and their properties.
- Updated sidebar styles for better layout and appearance.
