[FEATURE REQUEST] Support more STL containers

[jharmer95]

Feature Request: Support more STL containers

Brief Summary of Request

Currently, this library only supports sequential containers like std::vector and std::array, but other container types should also have built-in support.

These include:

• [x] std::array
• [x] std::vector
• [x] std::deque
• [x] std::forward_list
• [x] std::list
• [x] std::set
• [x] std::map
• [x] std::multiset
• [x] std::multimap
• [x] std::unordered_set
• [x] std::unordered_map
• [x] std::unordered_multiset
• [x] std::unordered_multimap

As well as container adapters:

• [ ] std::stack
• [ ] std::queue
• [ ] std::priority_queue

And a few other popular data structures:

• [ ] std::complex
• [x] std::pair
• [x] std::tuple

What Is The Value Added With This Feature

Easier serialization without user-defined functions.

Desired Outcome

// server
void UseMap(std::map<int, std::string> map);

// client
MyClient client;
std::map<int, std::string> my_map;

client.call_func("UseMap", my_map);

Other Details

This may be updated/replaced when C++20 is adopted.

[jharmer95]

It would be nice to have the support for containers be in separate headers (like adapters) to reduce the number of STL dependencies of #include <rpc.hpp> (at least until C++20).