Update T1003.007 dump_heap.py: refactor FreeBSD heap memory dumping logic

[vl43den]

Details:

Previously on FreeBSD, i suspect the branch contained a problematic variable assignment error:

mem_start = mem_stop

in my tests this often resulted in a line 37 error:

OSError: [Errno 14] Bad address (*as also seen in my Testing area below)

Dump_heap.py now:

• Accepts a PID and output filepath as arguments.
• On Linux branch it still parses /proc//maps to locate the [heap] mapping and
  dumps the corresponding region from /proc//mem.
• On FreeBSD, uses procstat -v <pid> to more reliably locate a heap-like rw mapping
  and dumps that region via /proc//mem.

These changes make the T1003.007 Python atomic more portable across
Linux and FreeBSD while keeping the behavior aligned with the existing
/proc-based credential dumping scenario. I still have to note that error
handling could be done even better, this was on the rather critical side!

Testing:

Testing was performed locally/manually on a FreeBSD 14.1-RELEASE releng/14.1-n267679-10e31f0946d8 GENERIC amd64:
*

my patch:

heap_maker.py script:

import time
import os
#large list allocation to ensure a heap segment exists
data = [i for i in range(1000000)]
print(f"Heap Maker running with PID: {os.getpid()}")
# Keep the script running
time.sleep(3600)

Associated Issues: