HAL 9000 (v2)

This is an update to v1 of my HAL 9000: https://www.thingiverse.com/thing:2774212

Major changes:
- includes a TFT display, [glowing like HAL in the movie when interacting with mycroft](https://streamable.com/xvl5tx) (integrated into mycroft accordingly); the TFT display is attached via an USB connected FT232h
- front side grill is not printed anymore; a wire mesh is used for much improved acoustics (the two microphones are located behind that wire mesh)

Minor changes:
- (optionally) using two mini turnbuckles on the backside for holding the two case parts together
- (optionally) using a large size heat-shrink tube to wrap the ReSpeaker in order to better conceal it behind the mesh (see picture #1 vs. #2)
- various minor optimizations in both case halves

BOM:
- Raspberry Pi 4 (highly recommended over 3B)
- [ReSpeaker 2-Mics Pi HAT](https://wiki.seeedstudio.com/ReSpeaker_2_Mics_Pi_HAT/)
- IDC/40pin extender cable 20-30cm
- USB A-C corner adapter or USB A-C cable with