Fix socket-api byte order issue for systems where host byte order
and network byte order are the same:
- Document data structures used for storing IP addresses
- Fix bug in bind and connect methods by updating code in wasi_socket_ext
Implement wasi_addr_resolve function.
Also slightly modify the interface to make it more accessible for the end user:
- replace port argument with the service - so the user can actually get the port for a given service if unknown
- introduce __wasi_addr_info_t and use it as a buffer for addresses, instead of generic buffer
- introduce __wasi_addr_info_hints_t so user can enable filtering on the syscall level (and therefore use smaller buffers for addresses)
- add max_size parameter for the API as an output - in case the number of addresses is bigger than the buffer size, user can repeat the call with bigger buffer
This change is very minimalistic, and it doesn't include the followings:
1. implementation of getaddrinfo in the lib-socket
2. sample application
Which are to be added in the following change #1336
Refer to [Networking API design](https://github.com/WebAssembly/WASI/issues/370)
and [feat(socket): berkeley socket API v2](https://github.com/WebAssembly/WASI/pull/459):
- Support the socket API of synchronous mode, including `socket/bind/listen/accept/send/recv/close/shutdown`,
the asynchronous mode isn't supported yet.
- Support adding `--addr-pool=<pool1,pool2,..>` argument for command line to identify the valid ip address range
- Add socket-api sample and update the document
