Improve system_process_attributes on macOS (Bug#48548)

Improve system_process_attributes on macOS (Bug#48548)

* src/sysdep.c (system_process_attributes): Fix misprint in 'tty' attr
- should be 'ttname' instead.  Change 'utime', 'stime', 'time',
'majflt' attrs to obtain them from proc_pid_rusage, as sysctl call
used before doesn't give correct values; remove 'minflt' because it's
not available.  Obtain 'vsize' / 'rss' / 'thcount' from proc_pidinfo.
Use sysctl with KERN_PROCARGS2 to obtain args: value contains both
argc and argv, so argv can be reliably cut out.