pw_bloat/bloaty_config: Add log level flag and skip empty segments
pw_bloat/bloaty_config: Add log level flag and skip empty segments

Updates pw_bloat.bloaty_config to skip segments with a vmsize of 0
such as GNU_STACK segments.

Also adds a log level argument in order to make this script ready
to be used in builds.

Change-Id: I47e88257be2377f69652b0c66fe0fbd13392d4bc
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/85341
Reviewed-by: Alexei Frolov <a1b001416a8cf9aaea32a3411f8f3c0793ebc0b5@google.com>
Commit-Queue: Ewout van Bekkum <638f134dbc68778d6b859fb04a64baea2b00b021@google.com>
Pigweed-Auto-Submit: Ewout van Bekkum <638f134dbc68778d6b859fb04a64baea2b00b021@google.com>

google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed