If credentials are read from the Windows credential manager, and the **username** contains the **domain** portion (`domain\username`), a connection couldn't be establish.
This PR parses the username and domain, sets the correct properties in the settings structure pretty much the same way the CLI args handling is doing.
* Use new ConvertUtf8ToWChar, ConvertUtf8NToWChar,
ConvertUtf8ToWCharAlloc and ConvertUtf8NToWCharAlloc
* Use new ConvertWCharToUtf8, ConvertWCharNToUtf8,
ConvertWCharToUtf8Alloc and ConvertWCharNToUtf8Alloc
* Use new Stream UTF16 to/from UTF8 read/write functions
* Use new settings UTF16 to/from UTF8 read/write functions
* added wf_defaults.c (also in CMakeLists.txt) which provides the capability to read credential manager entries and set username and password in the rdpSettings accordingly
* the same will be done if a gateway host is specified without credentials
* the behavior will be similar to mstsc.exe on windows
