Remove TcpLoopbackFastPath and use of SIO_LOOPBACK_FAST_PATH

[mrotteveel]

Microsoft actively discourages using the SIO_LOOPBACK_FAST_PATH socket option:

Important The SIO_LOOPBACK_FAST_PATH is deprecated and is not recommended to be used in your code.

As such, the TcpLoopbackFastPath configuration option and the use of SIO_LOOPBACK_FAST_PATH should be removed from Firebird 5.0, and disabled by default in next versions of Firebird 3.0 and 4.0.