Upload methods should have a way to specify whether the debugger halts/resets on connect

[multiplemonomials]

Currently, the different suupported GDB servers do different things on connection:

• Some reset the chip, while others don't
• Some halt the chip, while others don't

To the extent possible, we should standardize this behavior and allow users to select what they want. Maybe make a number of different gdbserver targets such as gdb-halt-reset, gdb-reset, gdb-halt, and gdb-continue? It could also be a CMake variable but I think having the targets available might make things more convenient.