Temp files processing refactoring

[luzrain]

I propose some changes in the way we work with temporary files during the execution of the "status" and "connections" commands.

Changes:

• I have added tho new properties $processStatusFile and $connectionStatusFile instead of $statusFile.
• Moved out initialization process of these properties to the init method.
• Changed the default paths to the system temp directory.
• Changed the way files are deleted after command execution. "connection" command didn't delete them at all.
• Added formatConnectionStatusData() method similar to formatStatusData() but for "connections" command output (it's needed to add the ability to override the way the message is printed).
• Print "connections" command output using the safeEcho() method.

Breaking changes:

• $statusFile property removed, replaced with $processStatusFile and $connectionStatusFile.

Breaking changes in protected scope:

May only affect those who have overridden the Workerman class.

• formatStatusData() method removed, replaced by formatProcessStatusData()
• $statisticsFile property removed

Other changes:
Pid file default path also uses system temp directory by default.
Sleep time during "status" command execution reduced to 0.5sec.

[luzrain]

One more thing I want to discuss. Do we even need the ability to set custom paths for status files since they are stored in the system temp directory by default? Maybe it's worth to removing $processStatusFile and $connectionStatusFile from the public scope at all? What do you think?

[luzrain]

I've found the reason why the original temp directories were changed, so it might be better to save temp files in the old place. It's up to you.
#629
Personally, I think it is a bad idea to save any temp files in the vendor directory.

[walkor]

Thank you very much for your PR.
I suggest keeping the statusFile so that old projects can be directly upgraded without making any changes.
The default value of pidFile is sys_get_temp_dir(), in Linux systems it is likely to be the /tmp directory, and many operating systems regularly clean up the /tmp directory, resulting in the loss of pid files.

[luzrain]

I returned public $statusFile and changed back default system temp paths 👌