Add ProcessRunner and PIDFile (#4225)

* feat(Foundation): PIDFile and ProcessRunner #4064
* feat(Thread): optional signal blocking on POSIX #2978
* fix(ProcessRunner):remove logger, code enhancement #4225
* feat(Foundation): add PIDFile and ProcessRunner Tests #4064
* fix(Foundation): failing ProcessRunner Test #4064
* fix(PIDFile): remove append argument #4064
* remove Windows TODO from ProcessRunner #4064
* feat(ProcessRunnerTest): add line to checkTimeout #4064
* fix(ProcessRunner): add done flag to run() #4064
* fix(ProcessRunnerTest): add missing pidFile argument #4064
* chore(ProcessRunner): remove comments #4064
* fix(ProcessRunner): add runCount flag #4064
* fix(test): SharedLibrary and Class tests paths
* fix(ProcessRunner): thread sanitizer reported data races #4064
* fix(build): pass env var to testrunner #4064
* chore(PIDFile): remove ; in comments #4064
* feat(ProcessRunner): add Win argument format #4064
* fix(Tests): add ProcessRunnerTest to vcxproj #4064
* fix(Tests): change path to TestApp #4064
* feat(Tests): windows processrunner tests #4064
* fix(Tests): duplicate  ProcessRunnerTest in TestSuite vcxproj  #4064
* fix(CodeQL): sw declaration hides variable  #4064
* fix test binaries path for cmake
* fix(Build): missing include/PIDFile.h buildWin #4064
* fix(Build): add PocoFoundation depend in buildWin #4064
* feat(ProcessRunner): test process launching multiple threads #2976

---------

Co-authored-by: Pavle <pavle@debian-gnu-linux-11.localdomain>
Co-authored-by: Alex Fabijanic <alex@pocoproject.org>

Foundation/include/Poco/Process_UNIX.h

@@ -23,6 +23,7 @@
 #include <unistd.h>
 #include <vector>
 #include <map>
+#include <atomic>
 
 
 namespace Poco {
@@ -42,7 +43,7 @@ public:
 	int tryWait() const;
 
 private:
-	pid_t _pid;
+	std::atomic<pid_t> _pid;
 };