Add support for BlackMagicProbe

[Grazfather]

Description/Motivation/Screenshots

This adds three things:

gef-bmp-remote command, to connect to a black magic probe. This is its own command because it connects to a tty instead of a host/port.

GefBMPRemoteSessionManager, which handles connecting and such.

ARMBlackMagicProbe, a new arch, which handles its own memory management and has different register names that e.g. openocd.

How Has This Been Tested ?

Using my black magic probe to connect, attach, and successfully debug a target.

• x86-32 (N/A)
• x86-64 (N/A)
• ARM
• AARCH64
• MIPS (N/A)
• POWERPC (N/A)
• SPARC (N/A)
• RISC-V (N/A)

Checklist

• My code follows the code style of this project.
• My change includes a change to the documentation, if required.
• If my change adds new code,
  adequate tests have been added.
• I have read and agree to the
  CONTRIBUTING document.

[hugsy]

Can you add some docs? For new people to use it

[hugsy]

All 🟢 let's go