implementation without Boost

[wakaztahir]

Submodules

This adds two or three submodules, The problem with that is users may not initialize the submodules after pulling latest changes and try to build and receive errors because submodules haven't been initialized, of course this can be easily fixed by just running the command git submodule update --init --recursive
We could detect that the folders are empty in CMakeLists and emit a warning for it to help users or not use git submodules.
This adds a off by default flag for asio, so users will be compiling with boost anyway.

Properties

1 - Uses standalone Asio (conditionally) + ixwebsocket, so most of code stays the same
2 - Uses thirdparty header only libraries for optional and filesystem that are C++ 11 so standard stays the same
3 - 404 display with http server has been removed, I couldn't integrate it
4 - Uses git submodules to setup third party libraries for easier upgrades
5 - Make sure to initialize the submodules before building the project
6 - ixwebsocket requires zlib use on windows

Provides an option for standalone asio fixing #62

[wakaztahir]

I will chunk this pull request, this must be hard to merge, I will make several pull requests that are easy to merge and do not result in submodules for user

[wakaztahir]

Please review this pull request before I can close it @kuafuwang, This pull request is completely good, To solve submodules I will be using FetchContent, if there's anything you'd like me to change, I can do it.
Only #63 hasn't been solved yet, which affects repo and this pull request.

[wakaztahir]

@kuafuwang If you don't respond, then I will have to fork this repo (from the time where it used to work) and then I won't be making pull requests for LspCpp and maintain my own fork instead.
There hasn't been any move to solve bug #63, neither any feedback for issues or pull requests. Also the newer versions launches threads like crazy for processing messages, even though it should use coroutines.
There are no plans to move away from boost as well. I have limited time, I have waited 3 weeks for the bug to be fixed or any response.

[kuafuwang]

@kuafuwang If you don't respond, then I will have to fork this repo (from the time where it used to work) and then I won't be making pull requests for LspCpp and maintain my own fork instead. There hasn't been any move to solve bug #63, neither any feedback for issues or pull requests. Also the newer versions launches threads like crazy for processing messages, even though it should use coroutines. There are no plans to move away from boost as well. I have limited time, I have waited 3 weeks for the bug to be fixed or any response.

sorry ,i had been busy these day. i will check it as soon as possible. thank you for your time and work.