Fixed spawn menu listing and display

- Removed NM Monitor Function from autorun
- Rolledback NM Monitor Entity.

- Added Thumbnail for the Monitor Entity
- Added material to /materials/entities folder.
- Added additional checks to the amplifier entity.

- Fixed Monitor being spawned inside the ground.
- Fixed Amplifier Entity on a empty category.

- Cleaned code
- Added support for multiple Media Player Entities
- FFT tables are only called when 'Sync' Input is Enabled.

Released [NM] Prop Pack