msports: Add stub implementations for ComDBOpen/ComDBClose
Msports is typically only used by driver implementations, but may be called to enumerate serial ports. Without the stub implemenations, the application would crash:
wine: Call from 7BC57297 to unimplemented function msports.dll.ComDBOpen, aborting
Return ERROR_ACCESS_DENIED (the only valid error code), and return an invalid handle. Also add ComDBClose, in case the application unconditionally tries to close the handle.