Using modern C++ facilities to reduce boost dependency

[sduzh]

We can reduce dependency on Boost by replacing parts of it with stdlib equivalents:

• boost::unordered_map -> c++ 11 std::unordered_map
• boost::mutex -> c++ 11 std::mutex
• boost::condition_variable -> c++ 11 std::condition_variable
• boost::lock_guard -> c++ 11 std::lock_guard
• boost::thread -> c++ 11 std::thread
• boost::shared_ptr -> c++ 11 std::shared_ptr
• boost::scoped_ptr -> c++ 11 std::unique_ptr
• boost foreach -> c++ 11 built-in range-based for
• boost::variant -> c++ 17 std::variant
• boost::scoped_array -> c++ 11 std::unique_ptr<T[]>
• boost::function -> c++ 11 std::function
• boost::bind -> c++ 11 lambda or std::bind
• boost::lexical_cast -> c++ std::to_string

[HappenLee]

Good idea. Maybe it is a time to consider update c++11 to c++17. This proposal: https://github.com/apache/incubator-doris/issues/3563 pr:https://github.com/apache/incubator-doris/pull/3626

[yangzhg]

we have upgrad to gcc 10 and c++17, you can start the above substitution

[yangzhg]

I have a pr to repalce filesystem #5579