Network fixes

[justanetworkgeek]

Locally merged two branches by accident so this became one but essentially this PR:

• Adds more handling options for C program stack dumps (controller and telnet)
• Adds bc to dockerfile for libxenon so it doesn't have to be installed each time for a kernel compile if dockerized toolchain is used
• changes the default hostname set from the LWIP driver to MACADDRESS-xenon to be unique for each console. This should help with DHCP and local DNS resolution. Specifically addressing flaky DHCP problems.
• Changes the MAC address reported by the LWIP driver to have colon separators. Display purposes only.

[InvoxiPlayGames]

getch() is blocking as defined in the UART functions, so the get_controller_data part of the loop wouldn't be hit after the first attempt. Should probably check if kbhit() first.

[justanetworkgeek]

Thanks for catching I will fix that!

[justanetworkgeek]

Further testing

• DHCP works stably now on my network if I use various switches but didn't it before. Hostname always gets properly detected and rebound to existing DHCP leases. Previously only worked sometimes OR if console was plugged directly into router.
• telnet_console works to acknowledge a C program stack dump as do UART and controller
• verified MAC address colon separators appear fine when the function is called from libxenon

@InvoxiPlayGames this is all I had planned to contribute in this PR for your information. Please merge if tested on your side and satisfactory.