* make Poco::ActiveThreadPool easy to use (#4544)
* code format
* Fix ThreadSanitizer thread leak error
* enh(ActivePooledThread): Change pointers to references
* enh(ActivePooledThread): remove unused method
* enh(Poco::ActiveThreadPool): Use std::unique_ptr instead of raw pointer
* enh(Poco::ActiveThreadPool): Use C++ static_cast instead of C casting
* enh(Poco::ActiveThreadPool): Use standard containers instead of implementing own
* enh(Poco::ActiveThreadPool): Change pointer to reference
* enh(Poco::ActiveThreadPool): Use smart pointers instead of bare pointers
* enh(Poco::ActiveThreadPool): Fix codeql warning: A stack address which arrived via a may be assigned to a non-local variable.
* enh(Poco::ActiveThreadPool): More test case
* enh(Poco::ActiveThreadPool): std::optional::value unavailable on earlier macOS versions
* enh(Poco::ActiveThreadPool): Fix compare function for make heap
* enh(Poco::ActiveThreadPool): Add more test case
* enh(Poco::ActiveThreadPool): Add more test case
* enh(Poco::ActiveThreadPool): Code style
* enh(Poco::ActiveThreadPool): Test case
* enh(Poco::ActiveThreadPool): Test case
* enh(Poco::ActiveThreadPool): Fix test case error
* Revert "enh(Poco::ActiveThreadPool): std::optional::value unavailable on earlier macOS versions"
This reverts commit cba4673b47.
* enh(macOS): require min deployment macOS version 10.15 which has full support for C++17
* enh(Poco::ActiveThreadPool): Remove useless "{}"
* enh(Poco::ActiveThreadPool): Rename member variable m_impl to _impl
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Co-authored-by: Matej Kenda <matejken@gmail.com>
