Use prctl syscall to enable ptrace + replace stress-ng with custom stress cpu/mem code

[allantargino]

• removed stress-ng with custom code to allow ptrace in machines with yama's ptrace_scope = 1
  • all integration test scenarios now invoke ProcDumpTestApplication directly with arguments for CPU and memory stress
• re-enabling unit tests in Azure Pipelines
• moved high_cpu_custom_core_file_name.sh logic to custom_core_file_name.sh
  • In the previous test, the shell script launched ProcDump directly passing stress-ng PID. This change keeps this behavior of testing passing a PID + passing a file dump name as arguments.