This adds detection of UART core dumps to IDF monitor. By default,
core dumps are not printed to the console, but are processed by
espcoredump.py using 'info_corefile' command. The result is printed
to stdout.
This feature can be disabled in menuconfig.
In the future this can be extended to allow running espcoredump.py
with 'dbg_corefile' argument, which is similar to the current GDB Stub
behavior.
Related to IDF-52.